### Question:
RecursivePropertiesPersister implements PropertiesPersister { @Override public void store(Properties props, OutputStream os, String header) throws IOException { propertiesPersister.store(props, os, header); } RecursivePropertiesPersister(PropertiesPersister propertiesPersister); @Override void load(Properties props, InputStream is); @Override void load(Properties props, Reader reader); @Override void store(Properties props, OutputStream os, String header); @Override void store(Properties props, Writer writer, String header); @Override void loadFromXml(Properties props, InputStream is); @Override void storeToXml(Properties props, OutputStream os, String header); @Override void storeToXml(Properties props, OutputStream os, String header,
            String encoding);  }### Answer:
@Test public void testStorePropertiesOutputStreamString() throws IOException { final Properties props = new Properties(); final OutputStream os = new ByteArrayOutputStream(); final String header = "Test"; testee.store(props, os, header); verify(propertiesPersister).store(props, os, header); }
@Test public void testStorePropertiesWriterString() throws Exception { final Properties props = new Properties(); final Writer os = new NullWriter(); final String header = "Test"; testee.store(props, os, header); verify(propertiesPersister).store(props, os, header); }