assertEquals(" f1: bar f3_success: bar", result);
result = "";
callbacks = new Callbacks("memory");
callbacks.add( fn1 );
callbacks.fire( "foo" );
callbacks.add( fn2 );
callbacks.fire( "bar" );
callbacks.remove(fn2);
callbacks.fire( "foobar" );
assertEquals(" f1: foo f2: foo f1: bar f2: bar f1: foobar", result);