code: def normalize_dtypes(dtypes):
      if not isinstance(dtypes, list):
          return [normalize_dtype(dtypes)]
      return [normalize_dtype(dtype) for dtype in dtypes]
  
imports: from __future__ import print_function, division, absolute_import
  import numpy
  import six.moves
  import imgaug
label_desc: Use image node_id 1 for calling a global function with example usage: normalize_dtypes(dtypes) and returns: unknown, list