Bias in catconv2d

[joihn]

hardnet v1 does not have conv2d bias. ptsemseg/models/hardnet.py:11

        self.add_module('conv', nn.Conv2d(in_channels, out_channels, kernel_size=kernel,
                                          stride=stride, padding=kernel//2, bias = False))

However, hardnetv2, which use catconv2d does have conv2d bias CatConv2d/catconv2d.py:39

        self.bias = nn.Parameter(torch.Tensor(out_channels))

Why does catconv2d has bias ? isn't it useless ?