public/build/static/application.js
function dfl(a, b, c) {
        switch (arguments.length) {
            case 2: return a != null ? a : b;
            case 3: return a != null ? a : b != null ? b : c;
            default: throw new Error("Implement me");
        }
    }
function dfl(a, b, c) {
        switch (arguments.length) {
            case 2: return a != null ? a : b;
            case 3: return a != null ? a : b != null ? b : c;
            default: throw new Error("Implement me");
        }
    }
function dfl ( a , b , c ) { switch ( arguments . length ) { case 2 : return a != null ? a : b ; case 3 : return a != null ? a : b != null ? b : c ; default : throw new Error ( "Implement me" ) ; } }
Pick the first defined of two or three arguments. dfl comes from default.
Pick the first defined of two or three arguments . dfl comes from default .