def insert_asm(self, addr, asm_code, before_label=False):
        """
        Insert some assembly code at the specific address. There must be an instruction starting at that address.

        :param int addr: Address of insertion
        :param str asm_code: The assembly code to insert
        :return: None
        """

        if before_label:
            self._inserted_asm_before_label[addr].append(asm_code)
        else:
            self._inserted_asm_after_label[addr].append(asm_code)