public void initialize(ProxyConfiguration conf) throws Exception {
        for (ProxyExtension extension : extensions.values()) {
            extension.initialize(conf);
        }
    }
@Test
    public void testInitialize() throws Exception {
        ProxyConfiguration conf = new ProxyConfiguration();
        extensions.initialize(conf);
        verify(extension1, times(1)).initialize(same(conf));
        verify(extension2, times(1)).initialize(same(conf));
    }