import torch.nn as nn


class GAP(nn.Module):
    """
        Global Average pooling
        Widely used in ResNet, Inception, DenseNet, etc.
     """
    def __init__(self):
        super(GAP, self).__init__()
        self.avgpool = nn.AdaptiveAvgPool2d((1, 1))

    def forward(self, x):
        x = self.avgpool(x)
        # x = x.view(x.shape[0], -1)
        return x


class Identity(nn.Module):
    def __init__(self):
        super(Identity, self).__init__()

    def forward(self, x):
        return x