@Test
  public void testHColumnDescriptorCachedMaxVersions() throws Exception {
    ColumnFamilyDescriptor familyDescriptor =
      ColumnFamilyDescriptorBuilder.newBuilder(FAMILY).setMaxVersions(5).build();
    // Verify the max version
    assertEquals(5, familyDescriptor.getMaxVersions());

    // modify the max version
    familyDescriptor = ColumnFamilyDescriptorBuilder.newBuilder(familyDescriptor)
      .setValue(Bytes.toBytes(HConstants.VERSIONS), Bytes.toBytes("8")).build();
    // Verify the max version
    assertEquals(8, familyDescriptor.getMaxVersions());
  }
Start up a mini cluster and put a small table of empty regions into it.
hbase-server/src/test/java/org/apache/hadoop/hbase/TestColumnFamilyDescriptorDefaultVersions.java