old_contents: """
  Tools for importing dependencies
  """
  import importlib
  
  
  def attempt_import(module, error_message):
      """Attempt import of a dependency
  
      If the dependency is not available, raise a RuntimeError with the appropriate message
  
      Parameters
      ----------
      module : string
          the module name
      error_message : string
          the error to raise if the module is not importable
  
      Returns
      -------
      mod : ModuleType
          the imported module
  
      Raises
      ------
      RuntimeError
      """
      try:
          return importlib.import_module(module)
      except ModuleNotFoundError:
          raise RuntimeError(error_message)
  
new_contents: """
  Tools for importing dependencies
  """
  import importlib
  
  
  def attempt_import(module, error_message):
      """Attempt import of a dependency
  
      If the dependency is not available, raise a RuntimeError with the appropriate message
  
      Parameters
      ----------
      module : string
          the module name
      error_message : string
          the error to raise if the module is not importable
  
      Returns
      -------
      mod : ModuleType
          the imported module
  
      Raises
      ------
      RuntimeError
      """
      # Python 3.6+ raises a ModuleNotFoundError if import fails
      # Previous python versions raise an ImportError instead
      # Here we make ModuleNotFoundError = ImportError for older Python versions
      try:
          ModuleNotFoundError
      except NameError:
          ModuleNotFoundError = ImportError
  
      try:
          return importlib.import_module(module)
      except ModuleNotFoundError:
          raise RuntimeError(error_message)
  
subject: fix ModuleNotFoundError in Python 3.5