libgdx/libgdx — pull request #1266 by jrenner (2014-01-30 05:39:39+00:00)
Title: better error handling of null style argument for TextButton

before this the error message on passing a null argument doesn't make it completely obvious what the problem is:

```
// pass null as style
Exception in thread "LWJGL Application" java.lang.IllegalArgumentException: style must be a TextButtonStyle.
```