The automatic "Add this" function in eclipse does not work correctly for methods: parameters are dropped.
Example:
We have:
before: performOperation(var1, var2);
Action: click on "Add 'this'" in hover-menu
result: this.performOperation();
Version: Eclipse Checkstyle Plugin 5.7.0.201402131929
Fixed in Branch https://sourceforge.net/p/eclipse-cs/git/ci/367_add_this_drops_params/tree/
and merged to master.