dimensions to reduce.
  * **keepdim** (*bool*) -- whether the output tensor has "dim"
    retained or not.

Keyword Arguments:
      out (Tensor, optional) -- the output tensor.
Example:
  >>> a = torch.randn(4, 4)
  >>> a
  tensor([[ 0.6451, -0.4866,  0.2987, -1.3312],
          [-0.5744,  1.2980,  1.8397, -0.2713],
          [ 0.9128,  0.9214, -1.7268, -0.2995],
          [ 0.9023,  0.4853,  0.9075, -1.6165]])
  >>> torch.amin(a, 1)
  tensor([-1.3312, -0.5744, -1.7268, -1.6165])
