code: func yaml_parser_remove_simple_key(parser *yaml_parser_t) bool {
  	i := len(parser.simple_keys) - 1
  	if parser.simple_keys[i].possible {
  		// If the key is required, it is an error.
  		if parser.simple_keys[i].required {
  			return yaml_parser_set_scanner_error(parser,
  				"while scanning a simple key", parser.simple_keys[i].mark,
  				"could not find expected ':'")
  		}
  	}
  	// Remove the key from the stack.
  	parser.simple_keys[i].possible = false
  	return true
  }
docs: // Remove a potential simple key at the current flow level.