@Test(expected = IllegalArgumentException.class)
  public void testAddDuplicateFamilies() {
    byte[] familyName = Bytes.toBytes("cf");
    ColumnFamilyDescriptor hcd =
      ColumnFamilyDescriptorBuilder.newBuilder(familyName).setBlocksize(1000).build();
    TableDescriptor htd = TableDescriptorBuilder.newBuilder(TableName.valueOf(name.getMethodName()))
      .setColumnFamily(hcd).build();
    assertEquals(1000, htd.getColumnFamily(familyName).getBlocksize());
    hcd = ColumnFamilyDescriptorBuilder.newBuilder(familyName).setBlocksize(2000).build();
    // add duplicate column
    TableDescriptorBuilder.newBuilder(htd).setColumnFamily(hcd).build();
  }
Test default value handling for memStoreFlushSize
hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestTableDescriptorBuilder.java