code: def expression(self):
      index = self.index
  
      if self.token("("):
          e = self.serial() or self.parallel() or self.op()
          if e and self.token(")"):
              return e
      self.index = index
      e = self.op()
      return e
  
imports: import re
label_desc: Use image node_id 5 for calling the GEParser obj's underlying member method code with example usage: obj.expression() and returns: e, e