replace Assert method in frequently used methods

The use of Assert.isTrue() is very time consuming when it is used
together with a Message.format(), as the message is created every time.
This causes a noticeable performance issue when used in methods that are
called often during the layout cycle.

Change-Id: I61665b374f3881a00dce0c77566a51c11693fbdd
Signed-off-by: Carsten Hiesserich <carsten.hie@gmail.com>
5 files changed