code: def test_powers(self):
      signal = constant_op.constant(
          np.squeeze(self.powers[0, :, :]), dtype=dtypes.int64
      )
      reconstruction = reconstruction_ops.overlap_and_add(
          signal, self.frame_hop
      )
  
      output = self.evaluate(reconstruction)
      string_output = [np.base_repr(x, self.bases[0]) for x in output]
      self.assertEqual(string_output, self.expected_string)
  
imports: from absl.testing import parameterized
  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 test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import array_ops_stack
  from tensorflow.python.ops import gradient_checker_v2
  from tensorflow.python.ops import gradients_impl
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops.signal import reconstruction_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 7 for calling the ReconstructionOpsTest obj's underlying member method code with example usage: obj.test_powers() without return types