fn pop_byte(&mut self) -> u8 {
        let sp = self.sp();

        let b = self.fetch_byte(sp);

        self.set_sp(sp + 1);

        b
    }
/// Retreive one byte from the stack and increment the stack pointer
Retreive one byte from the stack and increment the stack pointer
Retreive one byte from the stack and increment the stack pointer
fn pop_byte(&mut self) -> u8 {
        let sp = self.sp();
        let b = self.fetch_byte(sp);
        self.set_sp(sp + 1);
        b
    }
fn pop_byte ( & mut self ) -> u8 { let sp = self . sp ( ) ; let b = self . fetch_byte ( sp ) ; self . set_sp ( sp + 1 ) ; b }
Retreive one byte from the stack and increment the stack pointer
Retreive one byte from the stack and increment the stack pointer
&mut self
&mut self