+ @SuppressFBWarnings(value = "NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE",
+ justification = "SpotBugs does not grok checkArgument()")
+ private int offsetOf(final K key) {
+ final Integer offset = offsets.get(key);
+ checkArgument(offset != null, "Key %s present in input, but not in offsets %s", key, offsets);
+ return offset;
+ }
+