def _structure(struct, name, parameters, colon, comment, newline, struct_body):
  """Composes the top-level IR for an Emboss structure."""
  del colon, comment, newline  # Unused.
  struct_body.structure.source_location.start.CopyFrom(
      struct.source_location.start)
  struct_body.structure.source_location.end.CopyFrom(
      struct_body.source_location.end)
  struct_body.name.CopyFrom(name)
  if parameters.list:
    struct_body.runtime_parameter.extend(parameters.list[0].list)
  return struct_body