code: def add_task(self, keywords, context, rule):
          
          for keyword in keywords:
              self._tasks[keyword] = {'context': context, 'rule': rule}
docs: Map a function to a list of keywords
  
          Parameters
          ----------
          keywords : iterable of str
              sequence of strings which should trigger the given function
          context : Context
              A Context object created using desired function
          rule : tuple
              A tuple of integers, which act as relative indices using which data
              is extracted to be passed to the function passed via context.