default void postGetTableDescriptors(ObserverContext<MasterCoprocessorEnvironment> ctx,
    List<TableName> tableNamesList, List<TableDescriptor> descriptors, String regex)
    throws IOException {
  }
Called after a getTableDescriptors request has been processed.
@param ctx            the environment to interact with the framework and master
@param tableNamesList the list of table names, or null if querying for all
@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