@SuppressWarnings("unchecked")
    public <T> T getOrDefault(Key<T> key, T defaultValue) {
        Objects.requireNonNull(key, "key");
        Objects.requireNonNull(defaultValue, "defaultValue");
        T value = (T) typedMap.get(Objects.requireNonNull(key));
        if (value != null) {
            return value;
        }
        return defaultValue;
    }
Returns the value in the context, or {@code defaultValue} if absent.
zuul-core/src/main/java/com/netflix/zuul/context/SessionContext.java