code: def test_batched_placeholders_from_specs_invalid_mixing(self):
      with self.assertRaisesRegex(TypeError, "Specs must be all"):
          impl_helper.batched_placeholders_from_specs(
              {
                  "f1": tf.TensorSpec(dtype=tf.int64, shape=[None]),
                  "f2": tf.io.FixedLenFeature(
                      dtype=tf.int64, shape=[None]
                  ),
              }
          )
  
imports: import copy
  import os
  import numpy
  from packaging import version
  import pyarrow
  import tensorflow
  from tensorflow_transform import analyzers
  from tensorflow_transform import impl_helper
  from tensorflow_transform import schema_inference
  from tensorflow_transform import test_case
  from tensorflow_transform.output_wrapper import TFTransformOutput
  from tensorflow_transform.tf_metadata import schema_utils
label_desc: Use image node_id 4 for calling the ImplHelperTest obj's underlying member method code with example usage: obj.test_batched_placeholders_from_specs_invalid_mixing() without return types