old_contents: import pandas as pd
  from root_pandas import read_root
  from root_numpy import list_branches
  from pandas.util.testing import assert_frame_equal
  import os
  
  def test_read_write():
      df = pd.DataFrame({'x': [1,2,3]})
      df.to_root('tmp.root')
      df_ = read_root('tmp.root')
      os.remove('tmp.root')
  
  def test_persistent_index():
      df = pd.DataFrame({'index': [42, 0, 1], 'x': [1,2,3]})
      df = df.set_index('index')
      df.index.name = 'MyAwesomeName'
      df.to_root('tmp.root')
      assert('__index__MyAwesomeName' in list_branches('tmp.root'))
      df_ = read_root('tmp.root')
      assert_frame_equal(df, df_)
      os.remove('tmp.root')
  
  
new_contents: import pandas as pd
  from root_pandas import read_root
  from root_numpy import list_branches
  from pandas.util.testing import assert_frame_equal
  import os
  
  def test_read_write():
      df = pd.DataFrame({'x': [1,2,3]})
      df.to_root('tmp.root')
      df_ = read_root('tmp.root')
      os.remove('tmp.root')
  
  def test_persistent_index():
      df = pd.DataFrame({'index': [42, 0, 1], 'x': [1,2,3]})
      df = df.set_index('index')
      df.index.name = 'MyAwesomeName'
      df.to_root('tmp.root')
      assert('__index__MyAwesomeName' in list_branches('tmp.root'))
      df_ = read_root('tmp.root')
      assert_frame_equal(df, df_)
      os.remove('tmp.root')
  
      # See what happens if the index has no name
      df = pd.DataFrame({'x': [1,2,3]})
      df.to_root('tmp.root')
      df_ = read_root('tmp.root')
      assert_frame_equal(df, df_)
      os.remove('tmp.root')
  
  def test_chunked_reading():
      df = pd.DataFrame({'x': [1,2,3,4,5,6]})
      df.to_root('tmp.root')
  
      count = 0
      for df_ in read_root('tmp.root', chunksize=2):
          assert(not df_.empty)
          count += 1
  
      assert count == 3
      os.remove('tmp.root')
  
  
subject: Expand tests