fn to_vec(&self) -> Vec<u8> {
        let vec = BigInt::to_vec(&self.to_bigint());
        let mut v = vec![0; 32 - vec.len()];
        v.extend(&vec);
        v
    }
/// convert to vector and pad with zeros if necessary
convert to vector and pad with zeros if necessary
convert to vector and pad with zeros if necessary
fn to_vec(&self) -> Vec<u8> {
        let vec = BigInt::to_vec(&self.to_bigint());
        let mut v = vec![0; 32 - vec.len()];
        v.extend(&vec);
        v
    }
fn to_vec ( & self ) -> Vec < u8 > { let vec = BigInt :: to_vec ( & self . to_bigint ( ) ) ; let mut v = vec ! [ 0 32 vec len ( ) ] ; v . extend ( & vec ) ; v }
convert to vector and pad with zeros if necessary
convert to vector and pad with zeros if necessary
&self