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.
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 = {};
}