Function safe_call_slice 

pub fn safe_call_slice<const DATA_CAP: usize>(
    contract: [u8; 20],
    calldata: &[u8],
    value: &U,
    gas: u64,
    offset: usize,
) -> Option<(bool, usize, [u8; DATA_CAP])>

Same as the slice variant, except check the length of the code for the address first. If code doesn’t exist, then we return None.