### Question:
K1Coloring extends Algorithm<K1Coloring, HugeLongArray> { public K1Coloring( Graph graph, long maxIterations, int minBatchSize, int concurrency, ExecutorService executor, ProgressLogger progressLogger, AllocationTracker tracker ) { this.graph = graph; this.minBatchSize = minBatchSize; this.concurrency = concurrency; this.executor = executor; this.progressLogger = progressLogger; this.tracker = tracker; this.nodeCount = graph.nodeCount(); this.maxIterations = maxIterations; this.nodesToColor = new BitSet(nodeCount); if (maxIterations <= 0L) { throw new IllegalArgumentException("Must iterate at least 1 time"); } } K1Coloring(
        Graph graph,
        long maxIterations,
        int minBatchSize,
        int concurrency,
        ExecutorService executor,
        ProgressLogger progressLogger,
        AllocationTracker tracker
    ); @Override K1Coloring me(); @Override void release(); long ranIterations(); boolean didConverge(); BitSet usedColors(); HugeLongArray colors(); @Override HugeLongArray compute();  }### Answer:
@Test void testK1Coloring() { final String DB_CYPHER = "CREATE" + " (a)" + ",(b)" + ",(c)" + ",(d)" + ",(a)-[:REL]->(b)" + ",(a)-[:REL]->(c)"; var graph = fromGdl(DB_CYPHER); K1Coloring k1Coloring = new K1Coloring( graph, 1000, DEFAULT_BATCH_SIZE, 1, Pools.DEFAULT, ProgressLogger.NULL_LOGGER, AllocationTracker.empty() ); k1Coloring.compute(); HugeLongArray colors = k1Coloring.colors(); assertNotEquals(colors.get(0), colors.get(1)); assertNotEquals(colors.get(0), colors.get(2)); assertEquals(colors.get(1), colors.get(2)); }