Function write_bgra_pixels_to_tiff

pub fn write_bgra_pixels_to_tiff<'a>(
    source: &mut impl FnMut() -> Option<&'a [u8]>,
    (width_px, height_px): (u32, u32),
    output: &Path,
) -> Result<(), Box<dyn Error>>

FIXME: this might crash on buffers of length not divisible by 4