src/main/java/com/arpnetworking/logback/KeyValueEncoder.java
Map<String, Object> createSafeContext(
            final ILoggingEvent event,
            @Nullable final List<String> contextKeys,
            @Nullable final List<Object> contextValues) {
        return KeyValueSerializationHelper.createContext(this, event, contextKeys, contextValues);
    }
Map<String, Object> createSafeContext(
            final ILoggingEvent event,
            @Nullable final List<String> contextKeys,
            @Nullable final List<Object> contextValues) {
        return KeyValueSerializationHelper.createContext(this, event, contextKeys, contextValues);
    }
/* package private