code: def p_referenceInitializer(p):
      
      if p[1][0] == '$':
          try:
              p[0] = p.parser.aliases[p[1]]
          except KeyError:
              ce = CIMError(
                  CIM_ERR_FAILED,
                  _format("Unknown alias: {0!A}", p[1]))
              ce.file_line = (p.parser.file, p.lexer.lineno)
              raise ce
      else:
          p[0] = p[1]
docs: referenceInitializer : objectHandle
                              | aliasIdentifier