KStreamBuilder extends TopologyBuilder { public String newName(String prefix) { return prefix + String.format("%010d", index.getAndIncrement()); } KStreamBuilder(); KStream<K, V> stream(String... topics); KStream<K, V> stream(Serde<K> keySerde, Serde<V> valSerde, String... topics); KTable<K, V> table(String topic); KTable<K, V> table(Serde<K> keySerde, Serde<V> valSerde, String topic); KStream<K, V> merge(KStream<K, V>... streams); String newName(String prefix);  }
@Test public void testNewName() { KStreamBuilder builder = new KStreamBuilder(); assertEquals("X-0000000000", builder.newName("X-")); assertEquals("Y-0000000001", builder.newName("Y-")); assertEquals("Z-0000000002", builder.newName("Z-")); builder = new KStreamBuilder(); assertEquals("X-0000000000", builder.newName("X-")); assertEquals("Y-0000000001", builder.newName("Y-")); assertEquals("Z-0000000002", builder.newName("Z-")); }