code: def valid_params(params):
      """Checks if this combination of parameters is allowed by Keras"""
      return not (params["input_dims"][1] == 1 and params["unroll"])
  
imports: import unittest
  import numpy
  import os
  import shutil
  import tempfile
  import itertools
  import coremltools
  from coremltools._deps import _HAS_KERAS_TF, _HAS_KERAS2_TF
  from coremltools.models.utils import _macos_version, _is_macos
  import pytest
label_desc: Use image node_id 3 for calling a global function with example usage: valid_params(params) and returns: unknown