old_contents: # coding: utf-8
  """XGBoost: eXtreme Gradient Boosting library.
  
  Contributors: https://github.com/dmlc/xgboost/blob/master/CONTRIBUTORS.md
  """
  
  from __future__ import absolute_import
  
  import os
  
  from .core import DMatrix, Booster
  from .training import train, cv
  from . import rabit                   # noqa
  try:
      from .sklearn import XGBModel, XGBClassifier, XGBRegressor
      from .plotting import plot_importance, plot_tree, to_graphviz
  except ImportError:
      pass
  
  VERSION_FILE = os.path.join(os.path.dirname(__file__), 'VERSION')
  __version__ = open(VERSION_FILE).read().strip()
  
  __all__ = ['DMatrix', 'Booster',
             'train', 'cv',
             'XGBModel', 'XGBClassifier', 'XGBRegressor',
             'plot_importance', 'plot_tree', 'to_graphviz']
  
new_contents: # coding: utf-8
  """XGBoost: eXtreme Gradient Boosting library.
  
  Contributors: https://github.com/dmlc/xgboost/blob/master/CONTRIBUTORS.md
  """
  
  from __future__ import absolute_import
  
  import os
  
  from .core import DMatrix, Booster
  from .training import train, cv
  from . import rabit                   # noqa
  try:
      from .sklearn import XGBModel, XGBClassifier, XGBRegressor
      from .plotting import plot_importance, plot_tree, to_graphviz
  except ImportError:
      pass
  
  VERSION_FILE = os.path.join(os.path.dirname(__file__), 'VERSION')
  with open(VERSION_FILE) as f:
      __version__ = f.read().strip()
  
  __all__ = ['DMatrix', 'Booster',
             'train', 'cv',
             'XGBModel', 'XGBClassifier', 'XGBRegressor',
             'plot_importance', 'plot_tree', 'to_graphviz']
  
subject: modify __init__.py (#1587)