Function max_pool2d 

pub fn max_pool2d(
    x: Tensor<4>,
    kernel_size: [usize; 2],
    stride: [usize; 2],
    padding: [usize; 2],
    dilation: [usize; 2],
    ceil_mode: bool,
) -> Tensor<4>

Applies a 2D max pooling.