code: def get_metadata(data_dir=None):
      '''Obtain the metadata for all basis sets
  
      The metadata includes information such as the display name of the basis set,
      its versions, and what elements are included in the basis set
  
      The data is read from the METADATA.json file in the `data_dir` directory.
  
      Parameters
      ----------
      data_dir : str
          Data directory with all the basis set information. By default,
          it is in the 'data' subdirectory of this project.
      '''
  
      data_dir = fix_data_dir(data_dir)
      metadata_file = os.path.join(data_dir, "METADATA.json")
      return fileio.read_metadata(metadata_filef get_metadata(data_dir=None):
      '''Obtain the metadata for all basis sets
  
      The metadata includes information such as the display name of the basis set,
      its versions, and what elements are included in the basis set
  
      The data is read from the METADATA.json file in the `data_dir` directory.
  
      Parameters
      ----------
      data_dir : str
          Data directory with all the basis set information. By default,
          it is in the 'data' subdirectory of this project.
      '''
  
      data_dir = fix_data_dir(data_dir)
      metadata_file = os.path.join(data_dir, "METADATA.json")
      return fileio.read_metadata(metadata_file)
docs: Obtain the metadata for all basis sets
  
      The metadata includes information such as the display name of the basis set,
      its versions, and what elements are included in the basis set
  
      The data is read from the METADATA.json file in the `data_dir` directory.
  
      Parameters
      ----------
      data_dir : str
          Data directory with all the basis set information. By default,
          it is in the 'data' subdirectory of this project.