private List<String> getAllNormal(String normalName) {
        List<String> results = null;
        for (int i = 0; i < size(); i++) {
            if (name(i).equals(normalName)) {
                if (results == null) {
                    results = new ArrayList<>(1);
                }
                results.add(value(i));
            }
        }
        if (results == null) {
            return Collections.emptyList();
        } else {
            return Collections.unmodifiableList(results);
        }
    }
Returns all header values associated with the name.
zuul-core/src/main/java/com/netflix/zuul/message/Headers.java