old_contents: """
  :py:mod:`pyinduct.registry` covers the interface for registration of bases (a base is a set of initial functions).
  """
  
  __all__ = ["register_base", "is_registered", "deregister_base", "get_base"]
  
  _registry = {}
  
  
  def is_registered(label):
      """
      Checks whether a specific label has already been registered.
  
      Args:
      label (str): Label to check for.
  
      Return:
          bool: True if registered, False if not.
      """
      if not isinstance(label, (str, bytes)):
          raise TypeError("Only strings allowed as labels!")
  
      return label in list(_registry.keys())
  
  
  def register_base(label, base, overwrite=False):
      """
      Register a basis to make it accessible all over the :py:mod:`pyinduct`
      framework.
  
      Args:
          base (:py:class:`.Base`): base to register
          label (str): String that will be used as label.
          overwrite: Force overwrite if a basis is already registered under this
              label.
      """
      if not isinstance(label, (str, bytes)):
          raise TypeError("Only strings allowed as labels!")
  
      new_base = _registry.get(label, None)
  
      if new_base is not None:
          if overwrite:
              deregister_base(label)
          else:
              raise ValueError("Function set '{0}' already in registry!".format(label))
  
      _registry[label] = base
  
  
  def deregister_base(label):
      """
      Removes a set of initial functions from the packages registry.
  
      Args:
          label (str): String, label of functions that are to be removed.
  
      Raises:
          ValueError: If label is not found in registry.
      """
      if not isinstance(label, (str, bytes)):
          raise TypeError("Only strings allowed as label!")
      if not is_registered(label):
          raise ValueError("Label '{0}' not found in registry!".format(label))
  
      del _registry[label]
  
  
  def get_base(label):
      """
      Retrieve registered set of initial functions by their label.
  
      Args:
          label (str): String, label of functions to retrieve.
  
      Return:
          initial_functions
      """
      base = _registry.get(label, None)
      if base is None:
          raise ValueError("No base registered under label '{0}'!".format(label))
      else:
          return base
  
new_contents: """
  :py:mod:`pyinduct.registry` covers the interface for registration of bases (a base is a set of initial functions).
  """
  
  __all__ = ["register_base", "is_registered", "deregister_base", "get_base"]
  
  _registry = {}
  
  
  def is_registered(label):
      """
      Checks whether a specific label has already been registered.
  
      Args:
      label (str): Label to check for.
  
      Return:
          bool: True if registered, False if not.
      """
      if not isinstance(label, (str, bytes)):
          raise TypeError("Only strings allowed as labels!")
  
      return label in list(_registry.keys())
  
  
  def register_base(label, base, overwrite=False):
      """
      Register a basis to make it accessible all over the :py:mod:`pyinduct`
      framework.
  
      Args:
          base (:py:class:`.Base`): base to register
          label (str): String that will be used as label.
          overwrite: Force overwrite if a basis is already registered under this
              label.
      """
      if not isinstance(label, (str, bytes)):
          raise TypeError("Only strings allowed as labels!")
  
      new_base = _registry.get(label, None)
  
      if new_base is not None:
          if overwrite:
              deregister_base(label)
          else:
              raise ValueError("Function set '{0}' already in registry!".format(label))
  
      _registry[label] = base
  
  
  def deregister_base(label):
      """
      Removes a set of initial functions from the packages registry.
  
      Args:
          label (str): String, label of functions that are to be removed.
  
      Raises:
          ValueError: If label is not found in registry.
      """
      if not isinstance(label, (str, bytes)):
          raise TypeError("Only strings allowed as label!")
      if not is_registered(label):
          raise ValueError("Label '{0}' not found in registry!".format(label))
  
      del _registry[label]
  
  
  def get_base(label):
      """
      Retrieve registered set of initial functions by their label.
  
      Args:
          label (str): String, label of functions to retrieve.
  
      Return:
          initial_functions
      """
      base = _registry.get(label, None)
      if base is None:
          raise ValueError("No base registered under label '{0}'!".format(label))
      else:
          return base
  
  
  def clear_registry():
      """
      Deregister all bases.
      """
      _registry.clear()
  
subject: Add clear registry function