i am using this plugin findbug to check my code.

unfortunnatly i can't find this rule :
Java Code:
RCN: Nullcheck of value previously dereferenced (RCN_REDUNDANT_NULLCHECK_WOULD_HAVE_BEEN_A_NPE)

A value is checked here to see whether it is null, but this value can't be null because it was previously dereferenced and if it were null a null pointer exception would have occurred at the earlier dereference. Essentially, this code and the previous dereference disagree as to whether this value is allowed to be null. Either the check is redundant or the previous dereference is erroneous.
I want to add this rule to find that kind of bug in my code, i don't know how can i add this rule , i tried to modifie the XML configuration of findbug but ot doesn't work.

can anybody help please !!!!!!