code: def add_exit(self, guard, dst, jk, ip):
          
          self.irsb.statements.append(Exit(guard, dst.con, jk, ip))
docs: Add an exit out of the middle of an IRSB.
          (e.g., a conditional jump)
          :param guard: An expression, the exit is taken if true
          :param dst: the destination of the exit (a Const)
          :param jk: the JumpKind of this exit (probably Ijk_Boring)
          :param ip: The address of this exit's source