@Test
  public void testFPR_DefaultNumBuckets() {
    member1.invoke(() -> {
      cache.set(new CacheFactory(getDistributedSystemProperties()).create());
      FixedPartitionAttributes fpa = createFixedPartition(QUARTER_1, true);
      createPartitionedRegion("Quarter", singletonList(fpa), 0, 40, 12,
          newQuarterPartitionResolver());
    });

    member2.invoke(() -> {
      cache.set(new CacheFactory(getDistributedSystemProperties()).create());
      FixedPartitionAttributes fpa = createFixedPartition(QUARTER_2, true);
      createPartitionedRegion("Quarter", singletonList(fpa), 0, 40, 12,
          newQuarterPartitionResolver());
    });

    member3.invoke(() -> {
      cache.set(new CacheFactory(getDistributedSystemProperties()).create());
      FixedPartitionAttributes fpa = createFixedPartition(QUARTER_3, true);
      createPartitionedRegion("Quarter", singletonList(fpa), 0, 40, 12,
          newQuarterPartitionResolver());
    });

    member4.invoke(() -> {
      cache.set(new CacheFactory(getDistributedSystemProperties()).create());
      FixedPartitionAttributes fpa = createFixedPartition(QUARTER_4, true);
      createPartitionedRegion("Quarter", singletonList(fpa), 0, 40, 12,
          newQuarterPartitionResolver());
    });

    member1.invoke(() -> putThroughDataStore("Quarter"));

    member1.invoke(() -> checkPrimaryData(QUARTER_1));
    member2.invoke(() -> checkPrimaryData(QUARTER_2));
    member3.invoke(() -> checkPrimaryData(QUARTER_3));
    member4.invoke(() -> checkPrimaryData(QUARTER_4));

    member1.invoke(() -> checkPrimaryBucketsForQuarter(1, 1));
    member2.invoke(() -> checkPrimaryBucketsForQuarter(1, 1));
    member3.invoke(() -> checkPrimaryBucketsForQuarter(1, 1));
    member4.invoke(() -> checkPrimaryBucketsForQuarter(1, 1));
  }
This tests validate that datastore member tries the put on itself as well as other datastores
as per primary FixedPartitionAttributes defined on datastores with only one bucket per
partition.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/partitioned/fixed/FixedPartitioningDUnitTest.java