public void fastPut(final long id, final V value) {
        if (earlyDuplicateCheck && contains(id)) {
            throw new IllegalArgumentException("duplicate key found in early check: " + id);
        }
        vla[0][0] = value;
        add(id);
    }
Same as put( id, value ) but duplicate check
is skipped for performance. Be aware that you
can get a duplicate exception later on if the
map is restructured!
with System parameter earlyDuplicateCheck=true you
can enforce the early duplicate check for debugging

@param id    the key to insert
@param value the value to insert object
@throws IllegalArgumentException for duplicates if enabled
main/src/main/java/cgeo/geocaching/brouter/util/CompactLongMap.java