code: def test4DRaggedTensorWithOneRaggedDimension(self):
      rt = ragged_factory_ops.constant(
          [
              [[[1, 2], [3, 4]], [[5, 6], [7, 8]]],
              [],
              [[[9, 10], [11, 12]]],
          ],
          ragged_rank=1,
      )
      st = self.evaluate(rt.to_sparse())
      self.assertAllEqual(
          st.values, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
      )
      self.assertAllEqual(
          st.indices,
          [
              [0, 0, 0, 0],  # index for value=1
              [0, 0, 0, 1],  # index for value=2
              [0, 0, 1, 0],  # index for value=3
              [0, 0, 1, 1],  # index for value=4
              [0, 1, 0, 0],  # index for value=5
              [0, 1, 0, 1],  # index for value=6
              [0, 1, 1, 0],  # index for value=7
              [0, 1, 1, 1],  # index for value=8
              [2, 0, 0, 0],  # index for value=9
              [2, 0, 0, 1],  # index for value=10
              [2, 0, 1, 0],  # index for value=11
              [2, 0, 1, 1],  # index for value=12
          ],
      )
      self.assertAllEqual(st.dense_shape, [3, 2, 2, 2])
  
imports: from tensorflow.python.eager import context
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gradients_impl
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops.ragged import ragged_factory_ops
  from tensorflow.python.ops.ragged import ragged_functional_ops
  from tensorflow.python.ops.ragged import ragged_tensor
  from tensorflow.python.platform import googletest
label_desc: Use image node_id 4 for calling the RaggedTensorToSparseOpTest obj's underlying member method code with example usage: obj.test4DRaggedTensorWithOneRaggedDimension() without return types