code: def _reg_name(self, reg_id):
          
          if reg_id >= X86_REG_ENDING:
              logger.warning("Trying to get register name for a non-register")
              return None
          cs_reg_name = self.cpu.instruction.reg_name(reg_id)
          if cs_reg_name is None or cs_reg_name.lower() == '(invalid)':
              return None
          return self.cpu._regfile._alias(cs_reg_name.upper())
docs: Translates a register ID from the disassembler object into the
          register name based on manticore's alias in the register file
  
          :param int reg_id: Register ID