I've tried using both:

```
NSClassFromString and objc_getclass 

```

to return a class, so I can create it at runtime, but both functions return nil for some classes, for example "TestClass". Note that NSClassFromString works for me for 99% of classes.

If I add 

```
[TestClass class];

```

before I call NSStringFromClass or objc\_getclass it, it works. and if I try to just create the class using a class reference, i.e.:

```
[TestClass alloc];

```

it works too. So how can I force the class to load at runtime so NSClassFromString or objc\_getclass will not return nil?