code: def _cast(self, x, dtype, use_gpu=False):
      with test_util.device(use_gpu):
          val = constant_op.constant(
              x, self._toDataType(np.array([x]).dtype)
          )
          cast = math_ops.cast(
              val, self._toDataType(dtype), name="cast"
          )
          return self.evaluate(cast)
  
imports: import numpy
  from tensorflow.python.eager import context
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import sparse_tensor
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_state_ops
  from tensorflow.python.ops import gradient_checker_v2
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import test
label_desc: Use image node_id 2 for calling the CastOpTest obj's underlying member method code with example usage: obj._cast(x, dtype, use_gpu) and returns: self