code: def testReadWriteString(self):
      spec = [
          specs.TensorSpec([3], tf.float32, "action"),
          [
              specs.TensorSpec([], tf.string, "camera"),
              specs.TensorSpec([3, 2], tf.float32, "lidar"),
          ],
      ]
      replay_table = table.Table(spec, capacity=3)
      variables = replay_table.variables()
      self.assertEqual(3, len(variables))
      self.assertAllEqual(
          ["Table/action:0", "Table/camera:0", "Table/lidar:0"],
          [v.name for v in variables],
      )
  
      expected_values = [
          1 * np.ones(spec[0].shape.as_list()),
          [b"foo", 3 * np.ones(spec[1][1].shape.as_list())],
      ]
      tensors = tf.nest.map_structure(
          lambda x, dtype: tf.convert_to_tensor(value=x, dtype=dtype),
          expected_values,
          [tf.float32, [tf.string, tf.float32]],
      )
  
      write_op = replay_table.write(0, tensors)
      read_op = replay_table.read(0)
      self.evaluate(tf.compat.v1.global_variables_initializer())
      self.evaluate(write_op)
      read_value_ = self.evaluate(read_op)
      self.assertAllClose(read_value_[0], expected_values[0])
      self.assertEqual(read_value_[1][0], expected_values[1][0])
      self.assertAllClose(read_value_[1][1], expected_values[1][1])
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import os
  import numpy
  import tensorflow
  from tf_agents import specs
  from tf_agents.replay_buffers import table
  from tensorflow.python.framework import test_util
label_desc: Use image node_id 9 for calling the TableTest obj's underlying member method code with example usage: obj.testReadWriteString() without return types