Javascript mapping of ScriptEngine bindings does not expose keys.

The pasted example shows it all.
In java the Map contains the declaration, in JS it doesn't. Retrieving the property using the property name
gets you the property.

// Works in Java.
//final ScriptEngineManager m = new ScriptEngineManager();
//final ScriptEngine e = m.getEngineByName("nashorn");
//e.eval("function doIt(){}");
//System.out.println(" Contains obj ? " + e.getBindings(ScriptContext.ENGINE_SCOPE).containsKey("doIt"));

// Doesn't work in JS
var se = new javax.script.ScriptEngineManager();
var e = se.getEngineByName("nashorn");
e.eval("function doIt(){}");
// The returned bindings is not iterable...
var b = e.getBindings(javax.script.ScriptContext.ENGINE_SCOPE);
// Returns nothing
for( k in b){
    print("K " + b[k]);
}
// returns the function
print(b["doIt"]);