def rehashing(self):
        survivor_values = [value for value in self.values if value is not None]
        self.size_table = next_prime(self.size_table, factor=2)
        self._keys.clear()
        self.values = [None] * self.size_table  # hell's pointers D: don't DRY ;/
        for value in survivor_values:
            self.insert_data(value)