how to use jQuery.sap.require

HI

I want to use jQuery sap require so I use declare like following

jQuery.sap.declare("sap.a.b.c");

define(function() {

var a = function testFn(){

return "test";

};

now I use in different file jQuery.sap.require("sap.a.b.c");

but in the debugger I see just sap.a.b and I cannot use sap.a.b.c.testFn()

what can be the problem?Example will be very helpful