function _isArrayOfValuePairs(el) {
  if (_.isArray(el)) {
    if (_.all(el, _isValuePair)) return true;
  }
  return false;
}
function _isArrayOfValuePairs(el) {
  if (_.isArray(el)) {
    if (_.all(el, _isValuePair)) return true;
  }
  return false;
}
function _isArrayOfValuePairs ( el ) { if ( _ . isArray ( el ) ) { if ( _ . all ( el , _isValuePair ) ) return true ; } return false ; }
/*
helper: find an array containing only special key-value pairs
e.g. 'galleryURL' (makes it easier to handle in DB)
/ * helper : find an array containing only special key - value pairs e . g . galleryURL ( makes it easier to handle in DB )