class_docstr: Test cases for tf.strings.lower.
code: def test_string_lower_2d(self):
      strings = [
          ["pigS on THE wIng", "aniMals"],
          [" hello ", "\n\tWorld! \r \n"],
      ]
  
      with self.cached_session():
          output = string_ops.string_lower(strings)
          output = self.evaluate(output)
          self.assertAllEqual(
              output,
              [
                  [b"pigs on the wing", b"animals"],
                  [b" hello ", b"\n\tworld! \r \n"],
              ],
          )
  
imports: from tensorflow.python.ops import string_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 2 for calling the StringLowerOpTest obj's underlying member method code with example usage: obj.test_string_lower_2d() without return types