code: function collectForms( keyphrase, synonyms, language = "en", morphologyData ) {
  	const collectFormsWithMorphologyData = primeMorphologyData( morphologyData );
  
  	return collectFormsWithMorphologyData( keyphrase, synonyms, language );
  }
docs: Retrieves morphological forms of words of the keyphrase and of each synonym phrase using the function that caches
  the results of previous calls of this function.
  
  @param {string} keyphrase The paper's keyphrase.
  @param {string} synonyms The paper's synonyms.
  @param {string} language The paper's language.
  @param {Object} morphologyData The available morphology data to be used by the getForms function (language specific).
  
  @returns {Object} Object with an array of keyphrase forms and an array of arrays of synonyms forms.