synchronized void collectLeafPages(Collection<PageWrapper> target) {
        this.pageByOffset.values().stream().filter(p -> !p.isIndexPage()).forEach(target::add);
    }
synchronized void collectLeafPages ( Collection < PageWrapper > target ) { this . pageByOffset . values ( ) . stream ( ) . filter ( p -> ! p . isIndexPage ( ) ) . forEach ( target :: add ) ; }
Collects all the leaf (isIndexPage() == false) PageWrappers into the given Collection.

@param target The Collection to collect into.