constructor(formID) {
    this.optionFields = optionFields
    this.optionFieldsRegEx = optionFieldsRegEx

    this.subtypes = defaultSubtypes

    /**
     * Util to remove contents of DOM Object
     * @param  {HTMLElement} element
     * @return {HTMLElement} element with its children removed
     */
    this.empty = empty

    /**
     * Hide or show an Array|HTMLCollection of elements containing a case-insensitive string
     * @param  {HTMLElement[]|HTMLCollection}   elems
     * @param  {string}  term  match textContent to this term
     * @param  {boolean} show  or hide elements
     * @return {HTMLElement[]}         filtered elements
     */
    this.filter = filter

    instanceDom[formID] = this
    return instanceDom[formID]
  }
Set defaults
@param {string} formID
@return {Dom} Dom Instance