code: def _dumpArrayDictToFile(filelike, arrayDict):
      
      metadataList = list()
      for arrayKey in sorted(arrayDict):
          array = arrayDict[arrayKey]
          if array.ndim == 1:
              metadata = _dumpArrayToFile(filelike, array)
          else:
              metadata = _dumpNdarrayToFile(filelike, array)
          metadata['arrayKey'] = arrayKey
          metadataList.append(metadata)
      return metadataList
docs: Function to serialize and write ``numpy.array`` contained in a dictionary
      to a file. See also :func:`_dumpArrayToFile` and :func:`_dumpNdarrayToFile`.
  
  
      :param filelike: can be a file or a file-like object that provides the
          methods ``.write()`` and ``.tell()``.
      :param arrayDict: a dictionary which values are ``numpy.array``, that are
          serialized to bytes and written to the filelike.
  
      :returns: a list of metadata dictionaries
          a metadata dictionary contains information necessary to restore the
          ``numpy.arrays`` from the file and the corresponding key from the
          arrayDict as 'arrayKey'.