code: def test_reduce_blocks_1(self):
      data = [Row(x=float(x)) for x in range(5)]
      df = self.sql.createDataFrame(data)
      with tf.Graph().as_default():
          # The placeholder that corresponds to column 'x'
          x_input = tf.placeholder(
              tf.double, shape=[None], name="x_input"
          )
          # The output that adds 3 to x
          x = tf.reduce_sum(x_input, name="x")
          # The resulting dataframe
          res = tfs.reduce_blocks(x, df)
      assert res == sum([r.x for r in data])
  
imports: from __future__ import print_function
  from pyspark import SparkContext
  from pyspark.sql import DataFrame, SQLContext
  from pyspark.sql import Row
  from pyspark.sql.functions import col
  import tensorflow
  import pandas
  import tensorframes
  from tensorframes.core import _java_api
label_desc: Use image node_id 19 for calling the TestCore obj's underlying member method code with example usage: obj.test_reduce_blocks_1() without return types