<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def __process_instr(self, instr, avoid, next_addr, initial_state, execution_state, trace_current):
 """Process a REIL instruction. Args: instr (ReilInstruction):
 Instruction to process. avoid (list):
 List of addresses to avoid while executing the code. next_addr (int):
 Address of the following instruction. initial_state (State):
 Initial execution state. execution_state (Queue):
 Queue of execution states. trace_current (list):
 Current trace. Returns: int: Returns the next address to execute. """

        # Process branch (JCC oprnd0, empty, oprnd2).
        if instr.mnemonic == ReilMnemonic.JCC:
            not_taken_addr = next_addr
            address, index = split_address(instr.address)

            logger.debug("[+] Processing branch: {:#08x}:{:02x} : {}".format(address, index, instr))

            # Process conditional branch (oprnd0 is a REGISTER).
            if isinstance(instr.operands[0], ReilRegisterOperand):
                next_ip = self.__process_branch_cond(instr, avoid, initial_state, execution_state, trace_current, not_taken_addr)

            # Process unconditional branch (oprnd0 is an INTEGER).
            else:
                next_ip = self.__process_branch_uncond(instr, trace_current, not_taken_addr)

        # Process the rest of the instructions.
        else:
            trace_current += [(instr, None)]

            self.__cpu.execute(instr)

            next_ip = next_addr

        return next_ip