def _frozen_stages(self):
    if (self.frozen_stages >= 0):
        for m in [self.conv1, self.bn1, self.conv2, self.bn2]:
            for param in m.parameters():
                param.requires_grad = False
    if (self.frozen_stages == 1):
        for param in self.layer1.parameters():
            param.requires_grad = False
def _frozen_stages(self):
    if (self.frozen_stages >= 0):
        for m in [self.conv1, self.bn1, self.conv2, self.bn2]:
            for param in m.parameters():
                param.requires_grad = False
    if (self.frozen_stages == 1):
        for param in self.layer1.parameters():
            param.requires_grad = False