def METHOD_NAME():
    layer_record = LayerRecord(
        left=0,
        top=0,
        right=100,
        bottom=120,
        channel_info=[
            ChannelInfo(id=ChannelID.CHANNEL_0),
            ChannelInfo(id=ChannelID.USER_LAYER_MASK),
            ChannelInfo(id=ChannelID.REAL_USER_LAYER_MASK),
        ],
        mask_data=MaskData(
            left=20,
            top=20,
            right=80,
            bottom=90,
            real_left=10,
            real_top=10,
            real_right=90,
            real_bottom=100,
        )
    )
    channel_sizes = layer_record.channel_sizes
    assert len(channel_sizes) == 3
    assert channel_sizes[0] == (100, 120)
    assert channel_sizes[1] == (60, 70)
    assert channel_sizes[2] == (80, 90)