fix(net): FA1 -- repair fellowship builders, add 0x0290/0x0291, allegiance Kick

Campaign FA slice FA1 (lane B field-order sections §3.1-§3.7, lane C §3.2,
§1.4). Two latent acdream builder defects repaired, both cited in lane B
§5.2:

- BuildFellowshipCreate (0x00A2) invented a nonexistent "openness" byte
  and silently sent it as the low byte of shareXP -- ACE would read an
  INVERTED shareXP value. Corrected to retail's real shape: [str16L
  name][u32 shareXP]. shareXP is the FellowshipShareXP character option,
  not a dialog checkbox.
- BuildFellowshipUpdate(open:) mislabeled 0x00A6 as fellowship openness;
  it is FellowshipUpdateRequest -- panel VISIBILITY. Renamed to
  BuildFellowshipUpdateRequest(panelOpen:); the wire bytes were already
  correct, only the name/doc were wrong. ACE gates the whole 0x02C0
  member-vitals stream on this message (lane B §4.5) -- a prerequisite
  for live vitals once FA4 wires the panel.

Two builders added that acdream never had at all:

- BuildFellowshipAssignNewLeader (0x0290) -- retail's leader-Quit path
  sends this before 0x00A3 disband=0 (lane B §2.5).
- BuildFellowshipChangeOpenness (0x0291) -- the REAL openness toggle.
- AllegianceRequests.BuildKick -- wire-identical to BuildBreak (both are
  Event_BreakAllegiance 0x001E); named separately so FA2's panel command
  surface can distinguish "break from patron" from "kick a vassal" (lane
  C §1.4). AllegianceInfoRequest (0x027B) was already live via
  ClientCommandRequests.BuildAllegianceInfoRequest -- not duplicated.

Wrong-shape tests at SocialActionsTests.cs:53-105 re-pinned with
hand-computed golden byte vectors deriving each field from the cited
lane-B sections (not generated by calling the builder under test, per the
OP1 convention this file already follows for BuildSetCharacterOptions).
AllegianceRequestsTests.cs gained golden vectors for the existing
Swear/Break builders plus the new Kick alias.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
Erik 2026-08-12 00:12:47 +02:00
parent bb48d2c89d
commit 7be86f47f6
4 changed files with 264 additions and 35 deletions

View file

@ -3,25 +3,32 @@ using System.Buffers.Binary;
namespace AcDream.Core.Net.Messages; namespace AcDream.Core.Net.Messages;
/// <summary> /// <summary>
/// Outbound allegiance GameActions. Both Swear and Break carry a /// Outbound allegiance GameActions. Swear, Break, and Kick all carry a
/// single <c>uint32</c> target-guid payload inside the standard /// single <c>uint32</c> target-guid payload inside the standard
/// <c>0xF7B1</c> GameAction envelope. /// <c>0xF7B1</c> GameAction envelope.
/// ///
/// <para> /// <para>
/// Wire layout (r11 §2.1 / §2.3): /// Wire layout — byte-verified against
/// <c>docs/research/2026-08-11-fa-allegiance-wire.md</c> §3.2 (lane C),
/// three-way agreed with ACE + Chorizite there (the retail anchor is the
/// opcode literal store inside each <c>CM_Allegiance::Event_*</c> sender,
/// the strongest possible provenance):
/// <code> /// <code>
/// u32 0xF7B1 /// u32 0xF7B1
/// u32 gameActionSequence /// u32 gameActionSequence
/// u32 subOpcode (0x001D or 0x001E) /// u32 subOpcode (0x001D, 0x001E)
/// u32 targetGuid /// u32 targetGuid
/// </code> /// </code>
/// total 0x10 bytes for both. No change was needed here in Campaign FA
/// slice FA1 (2026-08-11) — the pre-existing shape already matched.
/// </para> /// </para>
/// ///
/// <para> /// <para>
/// Server replies with <c>GameEventAllegianceUpdate</c> (0x0020) and /// Server replies with <c>GameEventAllegianceUpdate</c> (0x0020) and
/// <c>GameEventAllegianceAllegianceUpdateDone</c> (0x01C8) on success, /// <c>GameEventAllegianceAllegianceUpdateDone</c> (0x01C8) on success,
/// or a <c>WeenieError</c> on failure (already sworn, already maxed /// or a <c>WeenieError</c> on failure (already sworn, already maxed
/// vassals, target not online, etc — see r11 §2.1 for the full list). /// vassals, target not online, etc — see lane C §2 master table for the
/// full list).
/// </para> /// </para>
/// </summary> /// </summary>
public static class AllegianceRequests public static class AllegianceRequests
@ -39,12 +46,32 @@ public static class AllegianceRequests
/// <summary> /// <summary>
/// Break your pledge to <paramref name="targetGuid"/>. Target can be /// Break your pledge to <paramref name="targetGuid"/>. Target can be
/// your patron (breaking from) OR your vassal (breaking them away). /// your patron (breaking from) OR your vassal (breaking them away).
/// Retail's Break button (element <c>0x10000264</c>) always targets
/// your own patron — see <see cref="BuildKick"/> for the vassal-facing
/// sibling button.
/// </summary> /// </summary>
public static byte[] BuildBreak(uint gameActionSequence, uint targetGuid) public static byte[] BuildBreak(uint gameActionSequence, uint targetGuid)
{ {
return Build(gameActionSequence, BreakOpcode, targetGuid); return Build(gameActionSequence, BreakOpcode, targetGuid);
} }
/// <summary>
/// Kick a vassal out of your allegiance. Wire-identical to
/// <see cref="BuildBreak"/> — both are <c>Event_BreakAllegiance(u32)
/// @0x006A69DA</c> (opcode <c>0x001E</c>); retail's Kick button
/// (<c>gmAllegianceUI::CloseKickConfirmationDialog @0x00490B00</c>)
/// targets the selected vassal (<c>m_iidPossibleKickedVassal</c>)
/// where Break targets <c>AllegianceProfile::GetPatron(self)</c> (lane
/// C §1.4). Named separately purely so FA2's panel command surface can
/// distinguish "break from patron" from "kick a vassal" without both
/// call sites reading like the same action; the golden vector is
/// identical to <see cref="BuildBreak"/>'s.
/// </summary>
public static byte[] BuildKick(uint gameActionSequence, uint vassalGuid)
{
return Build(gameActionSequence, BreakOpcode, vassalGuid);
}
private static byte[] Build(uint seq, uint sub, uint targetGuid) private static byte[] Build(uint seq, uint sub, uint targetGuid)
{ {
byte[] body = new byte[16]; byte[] body = new byte[16];

View file

@ -33,12 +33,24 @@ public static class SocialActions
public const uint QueryItemManaOpcode = 0x0263u; // u32 itemGuid; zero cancels public const uint QueryItemManaOpcode = 0x0263u; // u32 itemGuid; zero cancels
public const uint PingRequestOpcode = 0x01E9u; // no payload public const uint PingRequestOpcode = 0x01E9u; // no payload
// Fellowship // Fellowship — field orders byte-verified against
public const uint FellowshipCreateOpcode = 0x00A2u; // string16L name, bool openness, bool shareXP // docs/research/2026-08-11-fa-fellowship-wire.md §3.1-§3.7 (lane B),
public const uint FellowshipQuitOpcode = 0x00A3u; // bool disband // three-way agreed with ACE + holtburger there. Campaign FA slice FA1
// (2026-08-11) repaired two latent defects here (lane B §5.2): (a)
// FellowshipCreateOpcode's body never had an "openness" field — the
// prior builder invented one and silently sent it as the low byte of
// shareXP, which ACE would read as an INVERTED shareXP value; (b)
// FellowshipUpdateOpcode (0x00A6) is FellowshipUpdateRequest — panel
// VISIBILITY, not fellowship openness (that's the new 0x0291 below) —
// the prior "open" parameter name/doc was wrong even though its single
// bool byte happened to be in the right wire position.
public const uint FellowshipCreateOpcode = 0x00A2u; // string16L name, u32 shareXP
public const uint FellowshipQuitOpcode = 0x00A3u; // u32 disband (0/1)
public const uint FellowshipDismissOpcode = 0x00A4u; // u32 guid public const uint FellowshipDismissOpcode = 0x00A4u; // u32 guid
public const uint FellowshipRecruitOpcode = 0x00A5u; // u32 guid public const uint FellowshipRecruitOpcode = 0x00A5u; // u32 guid
public const uint FellowshipUpdateOpcode = 0x00A6u; // bool open public const uint FellowshipUpdateRequestOpcode = 0x00A6u; // u32 panelOpen (0/1) — panel visibility, NOT openness
public const uint FellowshipAssignNewLeaderOpcode = 0x0290u; // u32 newLeaderGuid
public const uint FellowshipChangeOpennessOpcode = 0x0291u; // u32 isOpen (0/1) — the REAL openness toggle
// Character options // Character options
// CH3 (2026-08-09): the full-blob SetCharacterOptions (0x01A1) builder // CH3 (2026-08-09): the full-blob SetCharacterOptions (0x01A1) builder
@ -119,21 +131,26 @@ public static class SocialActions
return body; return body;
} }
/// <summary>Create a fellowship with a chosen name + options.</summary> /// <summary>
public static byte[] BuildFellowshipCreate( /// Create a fellowship with a chosen name. There is no "openness"
uint seq, string fellowshipName, bool openness, bool shareXp) /// field on this message — retail's <c>gmFellowshipUI::CreateFellowship
/// @0x0048F730</c> writes exactly <c>[str16L name][u32 shareXP]</c>
/// (lane B §2.2/§3.1). <paramref name="shareXp"/> is the
/// <c>FellowshipShareXP</c> character option (<c>0x0F</c>), not a
/// dialog checkbox — retail reads
/// <c>PlayerModule::FellowshipShareXP</c> at create time and sends its
/// current value.
/// </summary>
public static byte[] BuildFellowshipCreate(uint seq, string fellowshipName, bool shareXp)
{ {
byte[] name = PackString16L(fellowshipName); byte[] name = PackString16L(fellowshipName);
// 2 bools consume 2 bytes + alignment pad to 4. byte[] body = new byte[12 + name.Length + 4];
int boolBlock = 2;
int pad = (4 - ((name.Length + boolBlock) & 3)) & 3;
byte[] body = new byte[12 + name.Length + boolBlock + pad];
BinaryPrimitives.WriteUInt32LittleEndian(body, GameActionEnvelope); BinaryPrimitives.WriteUInt32LittleEndian(body, GameActionEnvelope);
BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(4), seq); BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(4), seq);
BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(8), FellowshipCreateOpcode); BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(8), FellowshipCreateOpcode);
Array.Copy(name, 0, body, 12, name.Length); Array.Copy(name, 0, body, 12, name.Length);
body[12 + name.Length] = openness ? (byte)1 : (byte)0; BinaryPrimitives.WriteUInt32LittleEndian(
body[12 + name.Length + 1] = shareXp ? (byte)1 : (byte)0; body.AsSpan(12 + name.Length), shareXp ? 1u : 0u);
return body; return body;
} }
@ -156,14 +173,59 @@ public static class SocialActions
public static byte[] BuildFellowshipRecruit(uint seq, uint targetGuid) public static byte[] BuildFellowshipRecruit(uint seq, uint targetGuid)
=> SingleGuid(seq, FellowshipRecruitOpcode, targetGuid); => SingleGuid(seq, FellowshipRecruitOpcode, targetGuid);
/// <summary>Toggle fellowship open / closed recruiting.</summary> /// <summary>
public static byte[] BuildFellowshipUpdate(uint seq, bool open) /// Declare the fellowship panel's visibility to the server
/// (<c>0x00A6 FellowshipUpdateRequest</c>). This is NOT fellowship
/// openness — retail sends it from
/// <c>gmFellowshipUI::OnVisibilityChanged @0x0048E460</c> on panel
/// show/hide, and ACE gates the whole <c>0x02C0</c> member-vitals
/// stream on it (<c>Fellowship.cs:723</c>): a client that never sends
/// this sees names/levels/max-vitals from <c>0x02BE</c> but a roster
/// frozen at join time (lane B §4.5, §12). See
/// <see cref="BuildFellowshipChangeOpenness"/> for the real openness
/// toggle, which is a separate opcode this builder used to be
/// (incorrectly) named for.
/// </summary>
public static byte[] BuildFellowshipUpdateRequest(uint seq, bool panelOpen)
{ {
byte[] body = new byte[16]; byte[] body = new byte[16];
BinaryPrimitives.WriteUInt32LittleEndian(body, GameActionEnvelope); BinaryPrimitives.WriteUInt32LittleEndian(body, GameActionEnvelope);
BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(4), seq); BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(4), seq);
BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(8), FellowshipUpdateOpcode); BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(8), FellowshipUpdateRequestOpcode);
body[12] = open ? (byte)1 : (byte)0; body[12] = panelOpen ? (byte)1 : (byte)0;
return body;
}
/// <summary>
/// Transfer fellowship leadership to another member
/// (<c>0x0290 FellowshipAssignNewLeader</c>). Retail's Quit button, when
/// pressed by the current leader, sends this FIRST (targeting
/// <c>Fellowship::GetNonLeaderFellowID</c>) and only then sends
/// <c>0x00A3</c> disband=0 —
/// <c>gmFellowshipUI</c> Quit button case 8 @0x0049034B (lane B
/// §2.5/§3.6). <c>AssignLeadershipToFellow @0x0048F1E0</c> is the
/// direct (non-quit) caller.
/// </summary>
public static byte[] BuildFellowshipAssignNewLeader(uint seq, uint newLeaderGuid)
=> SingleGuid(seq, FellowshipAssignNewLeaderOpcode, newLeaderGuid);
/// <summary>
/// Toggle fellowship open / closed recruiting — the REAL openness
/// action (<c>0x0291 FellowshipChangeOpenness</c>). Retail's Open
/// button (case 9) calls
/// <c>Event_ChangeFellowOpeness @0x006A6040</c> after pre-toggling its
/// own <c>_open_fellow</c> optimistically (lane B §2.5/§3.7) — the
/// bytes are identical in shape to the old (misnamed)
/// <see cref="BuildFellowshipUpdateRequest"/>, but this is a distinct
/// opcode acdream did not previously send at all.
/// </summary>
public static byte[] BuildFellowshipChangeOpenness(uint seq, bool isOpen)
{
byte[] body = new byte[16];
BinaryPrimitives.WriteUInt32LittleEndian(body, GameActionEnvelope);
BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(4), seq);
BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(8), FellowshipChangeOpennessOpcode);
body[12] = isOpen ? (byte)1 : (byte)0;
return body; return body;
} }

View file

@ -32,4 +32,60 @@ public sealed class AllegianceRequestsTests
Assert.Equal(0xBBBBu, Assert.Equal(0xBBBBu,
BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(12))); BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(12)));
} }
// FA1: golden byte vectors, hand-computed from lane C §3.2
// (`CM_Allegiance::Event_SwearAllegiance`/`Event_BreakAllegiance`),
// not generated by calling the builder under test.
[Fact]
public void BuildSwear_GoldenByteVector()
{
byte[] body = AllegianceRequests.BuildSwear(gameActionSequence: 3, patronGuid: 0xAAAAu);
byte[] expected =
[
0xB1, 0xF7, 0x00, 0x00, // envelope 0xF7B1
0x03, 0x00, 0x00, 0x00, // seq 3
0x1D, 0x00, 0x00, 0x00, // opcode 0x001D
0xAA, 0xAA, 0x00, 0x00, // targetGuid 0xAAAA
];
Assert.Equal(expected, body);
}
[Fact]
public void BuildBreak_GoldenByteVector()
{
byte[] body = AllegianceRequests.BuildBreak(gameActionSequence: 5, targetGuid: 0xBBBBu);
byte[] expected =
[
0xB1, 0xF7, 0x00, 0x00, // envelope 0xF7B1
0x05, 0x00, 0x00, 0x00, // seq 5
0x1E, 0x00, 0x00, 0x00, // opcode 0x001E
0xBB, 0xBB, 0x00, 0x00, // targetGuid 0xBBBB
];
Assert.Equal(expected, body);
}
// New builder — BuildKick is BuildBreak's opcode with a vassal target
// (lane C §1.4). Same golden vector shape as BuildBreak, proving the
// wire is identical while the call site reads distinctly for FA2.
[Fact]
public void BuildKick_GoldenByteVector_SameShapeAsBreak()
{
byte[] body = AllegianceRequests.BuildKick(gameActionSequence: 6, vassalGuid: 0x50000042u);
byte[] expected =
[
0xB1, 0xF7, 0x00, 0x00, // envelope 0xF7B1
0x06, 0x00, 0x00, 0x00, // seq 6
0x1E, 0x00, 0x00, 0x00, // opcode 0x001E — SAME as Break
0x42, 0x00, 0x00, 0x50, // vassalGuid 0x50000042
];
Assert.Equal(expected, body);
Assert.Equal(AllegianceRequests.BreakOpcode,
BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8)));
}
} }

View file

@ -49,22 +49,48 @@ public sealed class SocialActionsTests
BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8))); BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8)));
} }
// FA1 (Campaign FA slice FA1, 2026-08-11): re-pinned per
// docs/research/2026-08-11-fa-fellowship-wire.md §3.1/§5.2(a). The
// PRIOR version of this test asserted a wrong shape — a fabricated
// "openness" byte at offset 20 that does not exist on the wire at all
// — pinning the SAME bug lane B found: ACE reads that byte as the low
// byte of a u32 shareXP, silently inverting it. The golden vector
// below is HAND-COMPUTED field-by-field from
// `CM_Fellowship::Event_Create @0x006A67A0` (`[u32 0xA2][str16L
// name][u32 shareXP]`, buffer size strPackSize+0x10), not generated by
// calling the builder under test — the OP1 convention
// (SocialActionsTests.cs:136-142 states the rule this file already
// follows for BuildSetCharacterOptions).
[Fact] [Fact]
public void BuildFellowshipCreate_StringThenBools() public void BuildFellowshipCreate_GoldenByteVector_StringThenShareXpU32()
{ {
byte[] body = SocialActions.BuildFellowshipCreate( byte[] body = SocialActions.BuildFellowshipCreate(
seq: 1, fellowshipName: "Team", openness: true, shareXp: false); seq: 7, fellowshipName: "Team", shareXp: true);
byte[] expected =
[
0xB1, 0xF7, 0x00, 0x00, // envelope 0xF7B1
0x07, 0x00, 0x00, 0x00, // seq 7
0xA2, 0x00, 0x00, 0x00, // opcode 0x00A2
0x04, 0x00, 0x54, 0x65, 0x61, 0x6D, 0x00, 0x00, // str16L "Team": u16 len=4, "Team", pad 2
0x01, 0x00, 0x00, 0x00, // shareXP = 1 (true) — a full u32, NOT a byte
];
Assert.Equal(expected, body);
Assert.Equal(SocialActions.FellowshipCreateOpcode, Assert.Equal(SocialActions.FellowshipCreateOpcode,
BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8))); BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8)));
// String at offset 12: u16 length = 4 }
ushort len = BinaryPrimitives.ReadUInt16LittleEndian(body.AsSpan(12));
Assert.Equal(4, len); [Fact]
Assert.Equal("Team", Encoding.ASCII.GetString(body.AsSpan(14, 4))); public void BuildFellowshipCreate_ShareXpFalse_EncodesZeroU32()
// string16L record = 2+4=6, pad 2 → advance by 8. {
// Then 2 bools at offset 20,21. byte[] body = SocialActions.BuildFellowshipCreate(
Assert.Equal(1, body[20]); // openness true seq: 1, fellowshipName: "X", shareXp: false);
Assert.Equal(0, body[21]); // shareXp false
// str16L "X": len=1, "X", pad to 4 => 4 bytes total (2+1+1 pad).
Assert.Equal(12 + 4 + 4, body.Length);
Assert.Equal(0u,
BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(body.Length - 4)));
} }
[Fact] [Fact]
@ -94,13 +120,71 @@ public sealed class SocialActionsTests
BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8))); BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8)));
} }
// FA1: renamed from BuildFellowshipUpdate/"open" — this opcode (0x00A6
// FellowshipUpdateRequest) is the panel-VISIBILITY declaration, not
// fellowship openness (lane B §3.5). The pinned byte shape is
// unchanged (SocialActionsTests.cs:98-105 pre-FA1 pinned the byte, not
// the meaning, so it survived the rename per lane B §5.2(b)) — this
// test just carries the corrected name.
[Fact] [Fact]
public void BuildFellowshipUpdate_HasOpenBool() public void BuildFellowshipUpdateRequest_GoldenByteVector_PanelOpenBool()
{ {
byte[] body = SocialActions.BuildFellowshipUpdate(seq: 1, open: true); byte[] body = SocialActions.BuildFellowshipUpdateRequest(seq: 9, panelOpen: true);
Assert.Equal(SocialActions.FellowshipUpdateOpcode,
byte[] expected =
[
0xB1, 0xF7, 0x00, 0x00, // envelope
0x09, 0x00, 0x00, 0x00, // seq 9
0xA6, 0x00, 0x00, 0x00, // opcode 0x00A6
0x01, 0x00, 0x00, 0x00, // panelOpen = 1
];
Assert.Equal(expected, body);
Assert.Equal(SocialActions.FellowshipUpdateRequestOpcode,
BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8)));
}
// New builder — 0x0290 FellowshipAssignNewLeader (lane B §2.5/§3.6).
// Golden vector hand-computed from `Event_AssignNewLeader
// @0x006A5F70`: `[u32 0x290][u32 newLeaderGuid]`, total 0x10.
[Fact]
public void BuildFellowshipAssignNewLeader_GoldenByteVector()
{
byte[] body = SocialActions.BuildFellowshipAssignNewLeader(seq: 2, newLeaderGuid: 0x50001234u);
byte[] expected =
[
0xB1, 0xF7, 0x00, 0x00, // envelope
0x02, 0x00, 0x00, 0x00, // seq 2
0x90, 0x02, 0x00, 0x00, // opcode 0x0290
0x34, 0x12, 0x00, 0x50, // newLeaderGuid 0x50001234
];
Assert.Equal(expected, body);
Assert.Equal(SocialActions.FellowshipAssignNewLeaderOpcode,
BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8)));
}
// New builder — 0x0291 FellowshipChangeOpenness, the REAL openness
// toggle (lane B §2.5/§3.7). Golden vector hand-computed from
// `Event_ChangeFellowOpeness @0x006A6040`: `[u32 0x291][u32 isOpen]`,
// total 0x10.
[Fact]
public void BuildFellowshipChangeOpenness_GoldenByteVector()
{
byte[] body = SocialActions.BuildFellowshipChangeOpenness(seq: 4, isOpen: false);
byte[] expected =
[
0xB1, 0xF7, 0x00, 0x00, // envelope
0x04, 0x00, 0x00, 0x00, // seq 4
0x91, 0x02, 0x00, 0x00, // opcode 0x0291
0x00, 0x00, 0x00, 0x00, // isOpen = 0 (false)
];
Assert.Equal(expected, body);
Assert.Equal(SocialActions.FellowshipChangeOpennessOpcode,
BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8))); BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8)));
Assert.Equal(1, body[12]);
} }
[Fact] [Fact]