weight given to each class. If given, it has to be a Tensor of
        size C. Otherwise, it is treated as if having all ones.
  * **size_average** (*bool**, **optional*) -- Deprecated (see
    "reduction"). By default, the losses are averaged over each
    loss element in the batch. Note that for some losses, there
    are multiple elements per sample. If the field "size_average"
    is set to "False", the losses are instead summed for each
    minibatch. Ignored when "reduce" is "False". Default: "None"

  * **ignore_index** (*int**, **optional*) -- Specifies a target
    value that is ignored and does not contribute to the input
    gradient. When "size_average" is "True", the loss is averaged
    over non-ignored targets.

  * **reduce** (*bool**, **optional*) -- Deprecated (see
    "reduction"). By default, the losses are averaged or summed
    over observations for each minibatch depending on
