パラメータがONの場合のみ既存メソッドを上書きする

pluginOverride.js

if (pluginParam) {
    var _Window_Message_processEscapeCharacter      = Window_Message.prototype.processEscapeCharacter;
    Window_Message.prototype.processEscapeCharacter = function(code, textState) {
        _Window_Message_processEscapeCharacter.apply(this, arguments);
        console.log('aaaa');
    };
}