core/lib/engine_http.js
function ensurePropertyIsAList(obj, prop) {
    obj[prop] = [].concat(
      typeof obj[prop] === 'undefined' ?
        [] : obj[prop]);
    return obj;
  }
function ensurePropertyIsAList(obj, prop) {
    obj[prop] = [].concat(
      typeof obj[prop] === 'undefined' ?
        [] : obj[prop]);
    return obj;
  }
function ensurePropertyIsAList ( obj , prop ) { obj [ prop ] = [ ] . concat ( typeof obj [ prop ] === 'undefined' ? [ ] : obj [ prop ] ) ; return obj ; }
Helper function to wrap an object's property in a list if it's defined, or set it to an empty list if not.
Helper function to wrap an object s property in a list if it s defined or set it to an empty list if not .