Map<String, String> getMutableMap() {
        return new Map<String, String>() {
            public void clear() {
                throw new UnsupportedOperationException();
            }

            public boolean containsKey(Object key) {
                throw new UnsupportedOperationException();
            }

            public boolean containsValue(Object value) {
                throw new UnsupportedOperationException();
            }

            public Set<Entry<String, String>> entrySet() {
                throw new UnsupportedOperationException();
            }

            public String get(Object key) {
                throw new UnsupportedOperationException();
            }

            public boolean isEmpty() {
                throw new UnsupportedOperationException();
            }

            public Set<String> keySet() {
                throw new UnsupportedOperationException();
            }

            public String put(String key, String value) {
                setParameter(key, value);
                return value;
            }

            public void putAll(Map<? extends String, ? extends String> m) {
                throw new UnsupportedOperationException();
            }

            public String remove(Object key) {
                throw new UnsupportedOperationException();
            }

            public int size() {
                throw new UnsupportedOperationException();
            }

            public Collection<String> values() {
                throw new UnsupportedOperationException();
            }
        };
    }