transformed dimensions. If given, each dimension "dim[i]" will
        either be zero-padded or trimmed to the length "s[i]" before
        computing the real FFT. If a length "-1" is specified, no
        padding is done in that dimension. Defaults to even output in
        the last dimension: "s[-1] = 2*(input.size(dim[-1]) - 1)".
  * **dim** (*Tuple**[**int**]**, **optional*) -- Dimensions to be
    transformed. The last dimension must be the half-Hermitian
    compressed dimension. Default: all dimensions, or the last
    "len(s)" dimensions if "s" is given.

  * **norm** (*str**, **optional*) --

    Normalization mode. For the forward transform ("hfftn()"),
    these correspond to:

    * ""forward"" - normalize by "1/n"

    * ""backward"" - no normalization

    * ""ortho"" - normalize by "1/sqrt(n)" (making the Hermitian
      FFT orthonormal)

    Where "n = prod(s)" is the logical FFT size. Calling the
