
        - Output: :math:`(N, C, T_{out}, H_{out}, W_{out})` or :math:`(C, T_{out}, H_{out}, W_{out})`, where
          :math:`(T_{out}, H_{out}, W_{out})=\text{output\_size}` or
          :math:`(T_{out}, H_{out}, W_{out})=\text{output\_ratio} \times (T_{in}, H_{in}, W_{in})`

    Examples:
        >>> # pool of cubic window of size=3, and target output size 13x12x11
        >>> m = nn.FractionalMaxPool3d(3, output_size=(13, 12, 11))
        >>> # pool of cubic window and target output size being half of input size
        >>> m = nn.FractionalMaxPool3d(3, output_ratio=(0.5, 0.5, 0.5))
        >>> input = torch.randn(20, 16, 50, 32, 16)
        >>> output = m(input)

    .. _Fractional MaxPooling:
        https://arxiv.org/abs/1412.6071
    rq