code: def test_groupby_1(self):
      data = [Row(x=float(x), key=str(x % 2)) for x in range(4)]
      df = self.sql.createDataFrame(data)
      gb = df.groupBy("key")
      with tf.Graph().as_default():
          x_input = tfs.block(df, "x", tf_name="x_input")
          x = tf.reduce_sum(x_input, [0], name="x")
          df2 = tfs.aggregate(x, gb)
      data2 = df2.collect()
      assert data2 == [Row(key="0", x=2.0), Row(key="1", x=4.0)], data2
  
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 22 for calling the TestCore obj's underlying member method code with example usage: obj.test_groupby_1() without return types