code: def get_list(self, key, fallback=None, split=","):
          
          fallback = fallback or []
          raw = self.get(key, None)
          if raw:
              return [value.strip() for value in raw.split(split)]
          return fallback
docs: Retrieve a value in list form.
  
          The interpolated value will be split on some key (by default, ',') and
          the resulting list will be returned.
  
          Arguments:
          key - the key to return
          fallback - The result to return if key isn't in the component.  By
                     default, this will be an empty list.
          split - The key to split the value on.  By default, a comma (,).