code: def test_op_dropout_bad_input(dropout_rate):
      from cntk import dropout
  
      a = C.input_variable(
          shape=(1, 2), dtype="float", needs_gradient=True, name="a"
      )
  
      with pytest.raises(ValueError):
          dropout_node = dropout(a, dropout_rate=dropout_rate)
  
imports: from __future__ import division
  import numpy
  import cntk
  import pytest
  from .ops_test_utils import unittest_helper, _test_unary_op, _test_binary_op, AA, precision, PRECISION_TO_TYPE, cntk_device
  from cntk.tests.test_utils import TOLERANCE_ABSOLUTE
  from cntk.internal.utils import eval
  from cntk.internal import sanitize_dtype_cntk
  from ..None import constant
  from cntk.variables import Parameter, Constant
label_desc: Use image node_id 11 for calling a global function with example usage: test_op_dropout_bad_input(dropout_rate) without return types