pub fn composite_glyphs16<'c, 'input, Conn>(
    conn: &'c Conn,
    op: PictOp,
    src: Picture,
    dst: Picture,
    mask_format: Pictformat,
    glyphset: Glyphset,
    src_x: i16,
    src_y: i16,
    glyphcmds: &'input [u8]
) -> Result<VoidCookie<'c, Conn>, ConnectionError>
where Conn: RequestConnection + ?Sized,