old_contents: import pandas as pd
  import numpy as np
  
  from yandextank.plugins.Aggregator.chopper import TimeChopper
  
  from conftest import MAX_TS, random_split
  
  
  class TestChopper(object):
      def test_one_chunk(self, data):
          chopper = TimeChopper([data], 5)
          result = list(chopper)
          assert len(result) == MAX_TS
          concatinated = pd.concat(r[1] for r in result)
          assert len(data) == len(concatinated), "We did not lose anything"
  
      def test_multiple_chunks(self, data):
          chunks = random_split(data)
          chopper = TimeChopper(chunks, 5)
          result = list(chopper)
          assert len(result) == MAX_TS
          concatinated = pd.concat(r[1] for r in result)
          assert len(data) == len(concatinated), "We did not lose anything"
  
      def test_partially_reversed_data(self, data):
          chunks = list(random_split(data))
          chunks[5], chunks[6] = chunks[6], chunks[5]
          chopper = TimeChopper(chunks, 5)
          result = list(chopper)
          assert (len(result) == MAX_TS,
                  "DataFrame is splitted into proper number of chunks")
          concatinated = pd.concat(r[1] for r in result)
          assert len(data) == len(concatinated), "We did not lose anything"
          assert np.allclose(concatinated.values,
                             data.values), "We did not corrupt the data"
  
new_contents: import pandas as pd
  import numpy as np
  
  from yandextank.plugins.Aggregator.chopper import TimeChopper
  
  from conftest import MAX_TS, random_split
  
  
  class TestChopper(object):
      def test_one_chunk(self, data):
          chopper = TimeChopper([data], 5)
          result = list(chopper)
          assert len(result) == MAX_TS
          concatinated = pd.concat(r[1] for r in result)
          assert len(data) == len(concatinated), "We did not lose anything"
  
      def test_multiple_chunks(self, data):
          chunks = random_split(data)
          chopper = TimeChopper(chunks, 5)
          result = list(chopper)
          assert len(result) == MAX_TS
          concatinated = pd.concat(r[1] for r in result)
          assert len(data) == len(concatinated), "We did not lose anything"
  
      def test_partially_reversed_data(self, data):
          chunks = list(random_split(data))
          chunks[5], chunks[6] = chunks[6], chunks[5]
          chopper = TimeChopper(chunks, 5)
          result = list(chopper)
          assert len(result) == MAX_TS, "DataFrame is splitted into proper number of chunks"
          concatinated = pd.concat(r[1] for r in result)
          assert len(data) == len(concatinated), "We did not lose anything"
          assert np.allclose(concatinated.values,
                             data.values), "We did not corrupt the data"
  
subject: fix assertion