* zero in shape start
* no assert for that
* if output size is 0, return without exec
* tweak
* strides
* reduce over non-zero
* shrink and expand
* fix import
* test_elementwise where
* cannot reshape from size 0 to size 1
* compiled backend reduce over 0
* zeros for numpy
* reduce over 0 and keepdim resulted in 1
* reduce empty set default values
* compare with same input
* pad test case
* cat test case
* torch does not support that?