docstr: Tests the string representation.
docstr_tok: ["Tests","the","string","representation","."]
code: def testStr(self):
      """Tests the string representation."""
      p1 = tpu_sharding.ShardingPolicy()
      self.assertEqual(str(p1), "ShardingPolicy(unset)")
      p1.set_number_of_shards(17)
      self.assertEqual(str(p1), "ShardingPolicy(unset)")
      p1.set_shard_dimension(8)
      self.assertEqual(str(p1), "ShardingPolicy(17 shards dimension 8)")
  
file_path: tensorflow-upstream/tensorflow/python/tpu/tpu_sharding_test.py
imports: from tensorflow.python.framework import tensor_shape
  from tensorflow.python.platform import test
  from tensorflow.python.tpu import tpu_sharding
label_desc: Use image node_id 3 for calling the ShardingTest obj's underlying member method code with example usage: obj.testStr() without return types