code: def _set_return_address(self, state, ret_addr):
          
  
          # TODO: the following code is totally untested other than X86 and AMD64. Don't freak out if you find bugs :)
          # TODO: Test it
  
          ret_bvv = state.solver.BVV(ret_addr, self.project.arch.bits)
  
          if self.project.arch.name in ('X86', 'AMD64'):
              state.stack_push(ret_bvv)
          elif is_arm_arch(self.project.arch):
              state.regs.lr = ret_bvv
          elif self.project.arch.name in ('MIPS32', 'MIPS64'):
              state.regs.ra = ret_bvv
          elif self.project.arch.name in ('PPC32', 'PPC64'):
              state.regs.lr = ret_bvv
          else:
              l.warning('Return address cannot be set for architecture %s. Please add corresponding logic to '
                        'VFG._set_return_address().', self.project.arch.name
                        )
docs: Set the return address of the current state to a specific address. We assume we are at the beginning of a
          function, or in other words, we are about to execute the very first instruction of the function.
  
          :param SimState state: The program state
          :param int ret_addr: The return address
          :return: None