lib/ext-underscore.js
function (a) {
    var elements = _.reject(_.rest(arguments), _.isMissing);
    return a.push.apply(a, elements);
  }
function (a) {
    var elements = _.reject(_.rest(arguments), _.isMissing);
    return a.push.apply(a, elements);
  }
function ( a ) { var elements = _ . reject ( _ . rest ( arguments ) , _ . isMissing ) ; return a . push . apply ( a , elements ) ; }
push only defined elements to the array
push only defined elements to the array