private Map<String, String> getBaggage() { Map<String, String> baggage = null; // optimization for 99% use cases, when there is only one parent if (references.size() == 1) { return references.get(0).getSpanContext().baggage(); } for (Reference reference: references) { if (reference.getSpanContext().baggage() != null) { if (baggage == null) { baggage = new HashMap<String, String>(); } baggage.putAll(reference.getSpanContext().baggage()); } } return baggage; }