@Override
        public void write(JmeExporter je) throws IOException {
            OutputCapsule capsule = je.getCapsule(this);

            capsule.writeSavableMap(testSavableMap, "testSavableMap", null);
            capsule.writeStringSavableMap(testStringSavableMap, "testStringSavableMap", null);
            capsule.writeIntSavableMap(testIntSavableMap, "testIntSavableMap", null);
        }
Test suite for implementations of the JmeExporter and JmeImporter interfaces.
There are tests here for all write* and read* methods of the OutputCapsule and InputCapsule interfaces respectively.
jme3-plugins/src/test/java/com/jme3/export/InputOutputCapsuleTest.java