code: def eval(self, expression, identify_erros=True):
      
      #print expression
      self._check_open()
      ret = self.client.Execute(expression)
      #print ret
      if identify_erros and ret.rfind('???') != -1:
        begin = ret.rfind('???') + 4
        raise MatlabError(ret[begin:])
      return ret
docs: Evaluates a matlab expression synchronously.
  
      If identify_erros is true, and the last output line after evaluating the
      expressions begins with '???' an excpetion is thrown with the matlab error
      following the '???'.
      The return value of the function is the matlab output following the call.