code: def test_transcode_utf8_with_bom(self):
      bom_string = b"\xef\xbb\xbfabcdefg"
      with self.cached_session() as sess:
          outputs = string_ops.unicode_transcode(
              bom_string,
              input_encoding="UTF-8",
              output_encoding="UTF-8",
          )
          values = self.evaluate(outputs)
          self.assertAllEqual(
              values, b"\xef\xbb\xbfabcdefg"
          )  # BOM preserved
  
          outputs = string_ops.unicode_transcode(
              bom_string,
              input_encoding="UTF-8",
              output_encoding="UTF-16-BE",
          )
          values = self.evaluate(outputs)
          utf16expected = bom_string.decode("UTF-8").encode("UTF-16-BE")
          self.assertAllEqual(values, utf16expected)
  
imports: from absl.testing import parameterized
  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 string_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 17 for calling the UnicodeTranscodeOpTest obj's underlying member method code with example usage: obj.test_transcode_utf8_with_bom() without return types