private void createTableWithCoprocessor(TableName tableName, String coprocessor)
    throws IOException {
    TableDescriptor tableDesc = TableDescriptorBuilder.newBuilder(tableName)
      .setColumnFamily(ColumnFamilyDescriptorBuilder.newBuilder(CF1_BYTES).build())
      .setColumnFamily(ColumnFamilyDescriptorBuilder.newBuilder(CF2_BYTES).build())
      .setCoprocessor(coprocessor).build();
    connection.getAdmin().createTable(tableDesc);
  }
Test coprocessor methods
{@link RegionObserver#postIncrementBeforeWAL(ObserverContext, Mutation, List)} and
{@link RegionObserver#postAppendBeforeWAL(ObserverContext, Mutation, List)}. These methods may
change the cells which will be applied to memstore and WAL. So add unit test for the case which
change the cell's column family and tags.
hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/TestPostIncrementAndAppendBeforeWAL.java