Hide Skill if another skill exists. (Skill replace)

/*: * @plugindesc Allows to hide certain skills, when the actor already knows a different skill. * <Iavra Hide Skills If Learned> * @author Iavra * * @param Notetag * @desc Notetag to be used to specify another skill id. If that skill is already learned by the actor, the tagged skill is hidden. * @default hide if learned: * * @param Include Traits * @desc If set to true, skills that have been added (temporarily) by traits will also be checked. * @default true * * @help * This plugin can be used to implement a simple skill tree. If you want a character to not show skill 1, if he already knows skill * 2, put this notetag in the notebox of skill 2: * * <hide if learned: 2> * * The parameter "Include Traits" can be used to include or exclude skills that have been (temporarily) added by traits. */(function() {    var _params = $plugins.filter(function(p) { return p.description.contains('<Iavra Hide Skills If Learned>'); })[0].parameters;    var _regex = new RegExp('<[ ]*' + _params['Notetag'] + '[ ]+(\\d+?)[ ]*>', 'g');    var _includeTraits = _params['Include Traits'].toLowerCase() === 'true';        var skillsToCheck = function(actor) {        return _includeTraits ? actor._skills.concat(actor.addedSkills()) : actor._skills;    };        (function($) {              /**        * If our notetag is present, we check if the actor already knows the given skill and hide it. We need to reset lastIndex of        * the regex, otherwise it will skill every second skill.        */        var _alias_includes = $.prototype.includes;        $.prototype.includes = function(skill) {            var match;            _regex.lastIndex = 0;            while((match = _regex.exec(skill.note))) {                if(skillsToCheck(this._actor).contains(Number(match[1]))) { return false; }            }            return _alias_includes.call(this, skill);        };           })(Window_SkillList);    })();

<hide if learned: 2>