over observations for each minibatch depending on
        "size_average". When "reduce" is "False", returns a loss per
        batch element instead and ignores "size_average". Default:
        "True"
  * **reduction** (*str**, **optional*) -- Specifies the reduction
    to apply to the output: "'none'" | "'batchmean'" | "'sum'" |
    "'mean'". "'none'": no reduction will be applied
    "'batchmean'": the sum of the output will be divided by the
    batchsize "'sum'": the output will be summed "'mean'": the
    output will be divided by the number of elements in the output
    Default: "'mean'"

  * **log_target** (*bool*) -- A flag indicating whether "target"
    is passed in the log space. It is recommended to pass certain
    distributions (like "softmax") in the log space to avoid
    numerical issues caused by explicit "log". Default: "False"

Return type:
      Tensor
Note:
 "size_average" and "reduce" are in the process of being
