Is there a way for me to make the following transformation with only tensor ops?  I.e. without writing my own for loop:
input:
tensor([[0, 0],
        [0, 1],
        [1, 1],
        [1, 1],
        [1, 1],
        [2, 1]])

output:
tensor([[0, 0],
        [0, 1],
        [1, 1],
        [2, 1]])

in other words, we have unique() to give me the unique scalar values but can i get the unique pairs in dim 0?