code: function( paper ) {
  	this.setPaper( paper );
  
  	this.defaultResearches = {
  		urlLength: urlLength,
  		wordCountInText: wordCountInText,
  		findKeywordInPageTitle: findKeywordInPageTitle,
  		calculateFleschReading: calculateFleschReading,
  		getLinkStatistics: getLinkStatistics,
  		getLinks: getLinks,
  		linkCount: linkCount,
  		imageCount: imageCount,
  		altTagCount: altTagCount,
  		matchKeywordInSubheadings: matchKeywordInSubheadings,
  		keywordCount: keywordCount,
  		getKeywordDensity: getKeywordDensity,
  		stopWordsInKeyword: stopWordsInKeyword,
  		stopWordsInUrl: stopWordsInUrl,
  		metaDescriptionLength: metaDescriptionLength,
  		keyphraseLength: keyphraseLength,
  		keywordCountInUrl: keywordCountInUrl,
  		firstParagraph: findKeywordInFirstParagraph,
  		metaDescriptionKeyword: metaDescriptionKeyword,
  		pageTitleWidth: pageTitleWidth,
  		wordComplexity: wordComplexity,
  		getParagraphLength: getParagraphLength,
  		countSentencesFromText: countSentencesFromText,
  		countSentencesFromDescription: countSentencesFromDescription,
  		getSubheadingTextLengths: getSubheadingTextLengths,
  		findTransitionWords: findTransitionWords,
  		passiveVoice: passiveVoice,
  		getSentenceBeginnings: getSentenceBeginnings,
  		relevantWords: relevantWords,
  		readingTime: readingTime,
  		getTopicDensity: getTopicDensity,
  		topicCount: topicCount,
  		sentences,
  		keyphraseDistribution: keyphraseDistribution,
  		morphology: morphology,
  		functionWordsInKeyphrase: functionWordsInKeyphrase,
  		h1s: h1s,
  	};
  
  	this._data = {};
  
  	this.customResearches = {};
  }
docs: This contains all possible, default researches.
  @param {Paper} paper The Paper object that is needed within the researches.
  @constructor
  @throws {InvalidTypeError} Parameter needs to be an instance of the Paper object.