"reduction"). By default, the losses are averaged or summed
        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'" | "'mean'" | "'sum'".
    "'none'": no reduction will be applied, "'mean'": the sum of
    the output will be divided by the number of elements in the
    output, "'sum'": the output will be summed. Note:
    "size_average" and "reduce" are in the process of being
    deprecated, and in the meantime, specifying either of those
    two args will override "reduction". Default: "'mean'"

Shape:
      * Input: (N, D) or (D) where D is the vector dimension.
  * Output: A Tensor of shape (N) if "reduction" is "'none'" and
    input shape is (N, D); a scalar otherwise.

Examples: