pub fn decode_u64(buf: &[u8]) -> u64 {
    let mut reader = Cursor::new(buf);
    // let it panic, If any invalid data.
    reader.read_u64::<LittleEndian>().unwrap()
}
/// decode_u64 is used to decode the buf.
decode_u64 is used to decode the buf.
decode_u64 is used to decode the buf .
pub fn decode_u64(buf: &[u8]) -> u64 {
    let mut reader = Cursor::new(buf);
    // let it panic, If any invalid data.
    reader.read_u64::<LittleEndian>().unwrap()
}
pub fn decode_u64 ( buf : & [ u8 ] ) -> u64 { let mut reader = Cursor :: new ( buf ) ; // let it panic, If any invalid data. reader . read_u64 :: < LittleEndian > ( ) . unwrap ( ) }
decode_u64 is used to decode the buf.
decode_u64 is used to decode the buf .
buf
&[u8]