code: def normalize_num_type(num_type):
      
      if isinstance(num_type, tf.DType):
          num_type = num_type.as_numpy_dtype.type
  
      if num_type in [np.float32, np.float64]:  # pylint: disable=E1101
          num_type = settings.float_type
      elif num_type in [np.int16, np.int32, np.int64]:
          num_type = settings.int_type
      else:
          raise ValueError('Unknown dtype "{0}" passed to normalizer.'.format(num_type))
  
      return num_type
docs: Work out what a sensible type for the array is. if the default type
      is float32, downcast 64bit float to float32. For ints, assume int32