formFieldReferencesKey = function (formField) {
      var referencedKey = _.isString(formField) ?
        formField :
        formField.key;
      if (!referencedKey) {
        return false;
      }
      return _.include(keys, referencedKey) ||
        !!_.find(keys, function (key) {
          return (referencedKey.indexOf(key + '.') === 0) ||
            (referencedKey.indexOf(key + '[]') === 0);
        });
    }
Helper function that parses the given field and returns true if
it references one of the keys to include directly. Note the function
does not parse the potential children of the field and will thus
return false even if the field actually references a key to include
indirectly.

@function
@param {Object} formField The form field to parse
@return {boolean} true when the field references one of the keys to
 include, false when not