docs: function (set, excepts, onlys) {
      debug("~ #filterOut");
      var hasExcepts = excepts && excepts.length > 0;
      if (onlys) {
          if (hasExcepts) {
              return onlys.filter(function (oel){
                  return !excepts.some(function (eel) { return eel === oel;});
              });
          } else {
              return onlys;
          }
      }
      if (hasExcepts) {
          return set.filter(function (oel){
              return !excepts.some(function (eel) { return eel === oel;});
          });
      } else {
          return set;
      }
  }