docs: def initialize_fields(self, content):
          """ Initializes the :class:`Field` members in the `Structure` with
          the *values* in the *content* dictionary.
  
          :param dict content: a dictionary contains the :class:`Field`
              values for each member in the `Structure`.
          """
          for name, value in content.items():
              item = self[name]
              # Container or Pointer
              if is_mixin(item):
                  item.initialize_fields(value)
              # Fields
              elif is_field(item):
                  item.value = value
              else:
                  raise MemberTypeError(self, item, name)