old_contents: """
  Template module to define control systems.
  """
  
  
  class ControlSystem(object):
      """ Define a control system to be used with a device
  
      It uses channel access to comunicate over the network with
      the hardware.
      """
      def __init__(self):
          raise NotImplementedError()
  
      def get(self, pv):
          raise NotImplementedError()
  
      def put(self, pv, value):
          raise NotImplementedError()
  
  
  class NullControlSystem(ControlSystem):
  
      def __init__(self):
          pass
  
      def get(self, pv):
          pass
  
      def put(self, pv, value):
          pass
  
new_contents: """
  Template module to define control systems.
  """
  
  
  class ControlSystem(object):
      """ Define a control system to be used with a device.
  
      It uses channel access to comunicate over the network with
      the hardware.
      """
      def __init__(self):
          raise NotImplementedError()
  
      def get(self, pv):
          """ Get the value of the given pv.
  
          Args:
              pv(string): The Pv to get the value of.
  
          Returns:
              Number: The numeric value of the pv.
          """
          raise NotImplementedError()
  
      def put(self, pv, value):
          """ Put the value of a given pv.
  
          Args:
              pv(string): The string to put the value for.
              value(Number): The value to be set.
          """
          raise NotImplementedError()
  
  
  class NullControlSystem(ControlSystem):
      """ Dummy control system to set the value of a pv."""
      def __init__(self):
          pass
  
      def get(self, pv):
          """ Get the value of the given pv.
  
          Args:
              pv(string): The Pv to get the value of.
  
          Returns:
              Number: The numeric value of the pv.
          """
          pass
  
      def put(self, pv, value):
          """ Put the value of a given pv.
  
          Args:
              pv(string): The string to put the value for.
              value(Number): The value to be set.
          """
          pass
  
subject: Add documentation for the control system