I have an example in sniffs
S->C: SMSG_SPELL_GO (0x132) Size: 77
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Caster GUID: { 0xF530006A8447E584, Type: Creature, Entry: 27268, Counter: 4711812 }
Spell Id: 48551 (Vengeful Stormhammer)
Cast Flags: Pending (0x410D)
Hit target: { 0xF130006AEF0029DD, Type: Creature, Entry: 27375, Counter: 10717 }
Target Flags: Unit | SourceLocation | DestLocation (0x62)
Transport GUID: { 0xF150006A690029D0, Type: Vehicle, Entry: 27241, Counter: 10704 }
Source Location: x = 0.2248, y = 0, z = 1.5676
Dest Location: x = 3801.67, y = -916.757, z = 159.681
Src guid is { 0xF150006A690029D0, Type: Vehicle, Entry: 27241, Counter: 10704 }
Dest guid is empty.