Initialize XorShiftRng and IsaacRng with seed

extern crate rand;
extern crate byteorder;

use byteorder::{ByteOrder, LittleEndian as LE};
use rand::{IsaacRng, XorShiftRng};

fn main() {
    let mut buf = [0; 16];
    {
        let (mut b1, mut b2) = buf.split_at_mut(8);
        byteorder::LittleEndian::write_u64(&mut b1, 123);
        byteorder::LittleEndian::write_u64(&mut b2, 123);
    }
    let random = Rc::new(RefCell::new(XorShiftRng::from_seed(buf)));
    let random = Rc::new(RefCell::new(IsaacRng::new_from_u64(123)));
}