code: private Expression generateSingleMsgVariable(MsgNode msgNode, String tmpVarName) {
      String googMsgVarName = buildGoogMsgVarNameHelper(msgNode);
  
      // Generate the goog.getMsg call.
      GoogMsgCodeGenInfo googMsgCodeGenInfo = genGoogGetMsgCallHelper(googMsgVarName, msgNode);
  
      if (!msgNode.isPlrselMsg()) {
        // No postprocessing is needed. Simply use the original goog.getMsg var.
        return googMsgCodeGenInfo.googMsgVar;
      }
      // For plural/select messages, generate the goog.i18n.MessageFormat call.
      // We don't want to output the result of goog.getMsg() directly. Instead, we send that
      // string to goog.i18n.MessageFormat for postprocessing. This postprocessing is where we're
      // handling all placeholder replacements, even ones that have nothing to do with
      // plural/select.
      return VariableDeclaration.builder(tmpVarName)
          .setRhs(getMessageFormatCall(googMsgCodeGenInfo))
          .build()
          .ref();
    }
docs: Returns a code chunk representing a variable declaration for an {@link MsgNode} with no
  fallback messages.