code: def testBasicSplit(self, texts, ragged_rank=None):
      input_tensor = ragged_factory_ops.constant_value(
          _nested_encode(texts, "UTF-8"),
          ragged_rank=ragged_rank,
          dtype=bytes,
      )
      result = ragged_string_ops.unicode_split(input_tensor, "UTF-8")
      expected = _nested_splitchars(texts, "UTF-8")
      self.assertAllEqual(expected, result)
  
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 errors
  from tensorflow.python.framework import sparse_tensor
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_string_ops
  from tensorflow.python.ops.ragged import ragged_factory_ops
  from tensorflow.python.ops.ragged import ragged_string_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 5 for calling the UnicodeSplitTest obj's underlying member method code with example usage: obj.testBasicSplit(texts, ragged_rank) without return types