code: def to_dict(mapreduce_yaml):
      
      all_configs = []
      for config in mapreduce_yaml.mapreduce:
        out = {
            "name": config.name,
            "mapper_input_reader": config.mapper.input_reader,
            "mapper_handler": config.mapper.handler,
        }
        if config.mapper.params_validator:
          out["mapper_params_validator"] = config.mapper.params_validator
        if config.mapper.params:
          param_defaults = {}
          for param in config.mapper.params:
            param_defaults[param.name] = param.default or param.value
          out["mapper_params"] = param_defaults
        if config.params:
          param_defaults = {}
          for param in config.params:
            param_defaults[param.name] = param.default or param.value
          out["params"] = param_defaults
        if config.mapper.output_writer:
          out["mapper_output_writer"] = config.mapper.output_writer
        all_configs.append(out)
  
      return all_configs
docs: Converts a MapReduceYaml file into a JSON-encodable dictionary.
  
      For use in user-visible UI and internal methods for interfacing with
      user code (like param validation). as a list
  
      Args:
        mapreduce_yaml: The Pyton representation of the mapreduce.yaml document.
  
      Returns:
        A list of configuration dictionaries.