default void postGetTableNames(ObserverContext<MasterCoprocessorEnvironment> ctx,
    List<TableDescriptor> descriptors, String regex) throws IOException {
  }
Called after a getTableNames request has been processed.
@param ctx         the environment to interact with the framework and master
@param descriptors the list of descriptors about to be returned
@param regex       regular expression used for filtering the table names
hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MasterObserver.java