写一个转换器，用OOP的方式设计

class TemperatureConverter:
    def __init__(self, unit):
        self.unit = unit

    def convert(self, value):
        pass

class CelsiusToFahrenheitConverter(TemperatureConverter):
    def __init__(self):
        super().__init__('Celsius')

    def convert(self, value):
        return (value * 9/5) + 32

class FahrenheitToCelsiusConverter(TemperatureConverter):
    def __init__(self):
        super().__init__('Fahrenheit')

    def convert(self, value):
        return (value - 32) * 5/9

# 使用示例
celsius_converter = CelsiusToFahrenheitConverter()
fahrenheit_converter = FahrenheitToCelsiusConverter()

celsius_value = 25
fahrenheit_value = 77

converted_fahrenheit = celsius_converter.convert(celsius_value)
converted_celsius = fahrenheit_converter.convert(fahrenheit_value)

print(f"{celsius_value} degrees Celsius is equal to {converted_fahrenheit} degrees Fahrenheit.")
print(f"{fahrenheit_value} degrees Fahrenheit is equal to {converted_celsius} degrees Celsius.")