class_docstr: The API necessary to provide a new Parquet reader/writer
docstr: Aggregate a list of metadata objects and optionally
  write out the final result as a _metadata file.
  
  Parameters
  ----------
  meta_list: list
      List of metadata objects to be aggregated into a single
      metadata object, and optionally written to disk. The
      specific element type can be engine specific.
  fs: FileSystem
  out_path: str or None
      Directory to write the final _metadata file. If None
      is specified, the aggregated metadata will be returned,
      and nothing will be written to disk.
  
  Returns
  -------
  If out_path is None, an aggregate metadata object is returned.
  Otherwise, None is returned.
docstr_tok: ["Aggregate","a","list","of","metadata","objects","and","optionally","write","out","the","final","result","as","a","_metadata","file",".","Parameters","--","--","--","--","--","meta_list",":","list","List","of","metadata","objects","to","be","aggregated","into","a","single","metadata","object",",","and","optionally","written","to","disk",".","The","specific","element","type","can","be","engine","specific",".","fs",":","FileSystem","out_path",":","str","or","None","Directory","to","write","the","final","_metadata","file",".","If","None","is","specified",",","the","aggregated","metadata","will","be","returned",",","and","nothing","will","be","written","to","disk",".","Returns","--","--","--","-","If","out_path","is","None",",","an","aggregate","metadata","object","is","returned",".","Otherwise",",","None","is","returned","."]
code: def aggregate_metadata(cls, meta_list, fs, out_path):
      """
      Aggregate a list of metadata objects and optionally
      write out the final result as a _metadata file.
  
      Parameters
      ----------
      meta_list: list
          List of metadata objects to be aggregated into a single
          metadata object, and optionally written to disk. The
          specific element type can be engine specific.
      fs: FileSystem
      out_path: str or None
          Directory to write the final _metadata file. If None
          is specified, the aggregated metadata will be returned,
          and nothing will be written to disk.
  
      Returns
      -------
      If out_path is None, an aggregate metadata object is returned.
      Otherwise, None is returned.
      """
      raise NotImplementedError()
  
imports: from __future__ import annotations
  import re
  import warnings
  import numpy
  import pandas
  from fsspec.core import expand_paths_if_needed, get_fs_token_paths, stringify_path
  from fsspec.spec import AbstractFileSystem
  from dask import config
  from dask.dataframe.io.utils import _is_local_fs
  from dask.utils import natural_sort_key, parse_bytes
label_desc: Use image node_id 9 for calling the Engine obj's underlying member method code with example usage: obj.aggregate_metadata(cls, meta_list, fs, out_path) without return types