code: func yaml_parser_parse_document_content(parser *yaml_parser_t, event *yaml_event_t) bool {
  	token := peek_token(parser)
  	if token == nil {
  		return false
  	}
  	if token.typ == yaml_VERSION_DIRECTIVE_TOKEN ||
  		token.typ == yaml_TAG_DIRECTIVE_TOKEN ||
  		token.typ == yaml_DOCUMENT_START_TOKEN ||
  		token.typ == yaml_DOCUMENT_END_TOKEN ||
  		token.typ == yaml_STREAM_END_TOKEN {
  		parser.state = parser.states[len(parser.states)-1]
  		parser.states = parser.states[:len(parser.states)-1]
  		return yaml_parser_process_empty_scalar(parser, event,
  			token.start_mark)
  	}
  	return yaml_parser_parse_node(parser, event, true, false)
  }
docs: // Parse the productions:
  // explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
  //                                                    ***********
  //