Function paste_sprites 

pub fn paste_sprites(
    sheet: &mut SpriteSheet,
    rect: &PixelRect,
    x0: i32,
    y0: i32,
    flags: Option<&[u8]>,
) -> PasteReport

Blit a pixel rectangle with its top-left at sheet pixel (x0, y0), overwriting in place. Pixels past the sheet edge are clipped. flags is one byte per covered 8x8 sprite (row-major); when Some, each byte overwrites the destination sprite’s flag byte.