第二章：视觉生成任务范式的迁移¶

import numpy as np
class Generator:
    def __init__(self):
        self.model = None

class GANModel:
    def __init__(self):
        self.generator = None
        self.discriminator = None

class DiffusionModel:
    def __init__(self):  
        self.noise_predictor = None