old_contents: from traits.api import HasTraits
  
  import json
  
  class Instrument(HasTraits):
  	"""
  	Main super-class for all instruments.
  	"""
  
  	def get_settings(self):
  		return self.__getstate__()
  
  	def set_settings(self, settings):
  		for key,value in settings.items():
  			setattr(self, key, value)
  
new_contents: from traits.api import HasTraits, Bool
  
  import json
  
  class Instrument(HasTraits):
  	"""
  	Main super-class for all instruments.
  	"""
  	enabled = Bool(True, desc='Whether the unit is used/enabled.')
  
  	def get_settings(self):
  		return self.__getstate__()
  
  	def set_settings(self, settings):
  		for key,value in settings.items():
  			setattr(self, key, value)
  
subject: Add enabled to top-level instrument class.