code: func yaml_parser_parse_stream_start(parser *yaml_parser_t, event *yaml_event_t) bool {
  	token := peek_token(parser)
  	if token == nil {
  		return false
  	}
  	if token.typ != yaml_STREAM_START_TOKEN {
  		return yaml_parser_set_parser_error(parser, "did not find expected <stream-start>", token.start_mark)
  	}
  	parser.state = yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE
  	*event = yaml_event_t{
  		typ:        yaml_STREAM_START_EVENT,
  		start_mark: token.start_mark,
  		end_mark:   token.end_mark,
  		encoding:   token.encoding,
  	}
  	skip_token(parser)
  	return true
  }
docs: // Parse the production:
  // stream   ::= STREAM-START implicit_document? explicit_document* STREAM-END
  //              ************