def get_field_ids(self):
    if (self.field_ids is None):
        self.field_ids = list()
        self.data.push_offset_and_seek(self.header.field_ids_off)
        for i in range(self.header.field_ids_size):
            self.field_ids.append(field_id_item(self.data, self))
        self.data.pop_offset_and_seek()
    return self.field_ids
def get_field_ids(self):
    if (self.field_ids is None):
        self.field_ids = list()
        self.data.push_offset_and_seek(self.header.field_ids_off)
        for i in range(self.header.field_ids_size):
            self.field_ids.append(field_id_item(self.data, self))
        self.data.pop_offset_and_seek()
    return self.field_ids