code: def _bias_scale(x, b, data_format):
      
      if data_format == 'NHWC':
          return x * b
      elif data_format == 'NCHW':
          return x * _to_channel_first_bias(b)
      else:
          raise ValueError('invalid data_format: %s' % data_format)
docs: The multiplication counter part of tf.nn.bias_add.