docs: def capability(self, cap_name):
  		""" Return capability by its name
  
  		:param cap_name: name of a capability to return
  		:return: bounded method or None (if a capability is not found)
  		"""
  		if cap_name in self.__class_capabilities__:
  			function_name = self.__class_capabilities__[cap_name]
  			return getattr(self, function_name)