code: function getWordCombinations( text, combinationSize, functionWords ) {
  	const sentences = getSentences( text );
  
  	let words, combination;
  
  	return flatMap( sentences, function( sentence ) {
  		sentence = sentence.toLocaleLowerCase();
  		sentence = normalizeQuotes( sentence );
  		words = getWords( sentence );
  
  		return filter( map( words, function( word, i ) {
  			// If there are still enough words in the sentence to slice of.
  			if ( i + combinationSize - 1 < words.length ) {
  				combination = words.slice( i, i + combinationSize );
  				return new WordCombination( combination, 0, functionWords );
  			}
  
  			return false;
  		} ) );
  	} );
  }
docs: Returns the word combinations for the given text based on the combination size.
  
  @param {string} text The text to retrieve combinations for.
  @param {number} combinationSize The size of the combinations to retrieve.
  @param {Function} functionWords The function containing the lists of function words.
  @returns {WordCombination[]} All word combinations for the given text.