question: private static < T extends PsiElement > boolean processChildrenOfType ( PsiElement element , Processor < T > processor , Class < T > psiClass , boolean reverseOrder ) { PsiElement child = reverseOrder ? element . getLastChild ( ) : element . getFirstChild ( ) ; while ( child != null ) { if ( psiClass . isInstance ( child ) ) { if ( ! processor . process ( ( T ) child ) ) { return true ; } } if ( processChildrenOfType ( child , processor , psiClass , reverseOrder ) ) { return true ; } child = reverseOrder ? child . getPrevSibling ( ) : child . getNextSibling ( ) ; } return false ; }
target:  Walk through entire PSI tree rooted at 'element', processing all children of the given type.