smap-shim.js
function(value) {
            if(value != value || value === 0) {
                for(var i = this.length; i-- && !is(this[i], value);){}
            } else {
                i = [].indexOf.call(this, value);
            }
            return i;
        }
function(value) {
            if(value != value || value === 0) {
                for(var i = this.length; i-- && !is(this[i], value);){}
            } else {
                i = [].indexOf.call(this, value);
            }
            return i;
        }
function ( value ) { if ( value != value || value === 0 ) { for ( var i = this . length ; i -- && ! is ( this [ i ] , value ) ; ) { } } else { i = [ ] . indexOf . call ( this , value ) ; } return i ; }
More reliable indexOf, courtesy of @WebReflection
More reliable indexOf courtesy of