RuntimeError: output with shape [1, 28, 28] doesn't match the broadcast shape [3, 28, 28] code example

Example: RuntimeError: output with shape [1, 28, 28] doesn't match the broadcast shape [3, 28, 28] site:stackoverflow.com

transform = transforms.Compose([transforms.ToTensor(),
  transforms.Normalize((0.5,), (0.5,))
])