[dist4]message_header // num_bytes
[u4]0 // version
[u4]0 // interface ID
[u4]15 // name
[u4]0 // flags
[u4]0 // padding
[anchr]message_header
[dist4]method15_params // num_bytes
[u4]0 // version
[dist8]enum_array_0 // param0
[u8]0 // param1
[anchr]method15_params
[anchr]enum_array_0
[dist4]enum_array_0_member // num_bytes
[u4]0 // num_elements
[anchr]enum_array_0_member
[u8]0x5678 // This is not part of the array above (which is
// empty), so enum validation shouldn't be done on
// it.