code: def testSum(self):
      for i in range(10):
          ds = dataset_ops.Dataset.range(1, i + 1)
          result = ds.reduce(np.int64(0), lambda x, y: x + y)
          self.assertEqual(((i + 1) * i) // 2, self.evaluate(result))
  
imports: import time
  from absl.testing import parameterized
  import numpy
  from tensorflow.python.data.experimental.ops import testing
  from tensorflow.python.data.kernel_tests import test_base
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import combinations
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  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 math_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import test
label_desc: Use image node_id 1 for calling the ReduceTest obj's underlying member method code with example usage: obj.testSum() without return types