default void postGetNamespaceDescriptor(ObserverContext<MasterCoprocessorEnvironment> ctx,
    NamespaceDescriptor ns) throws IOException {
  }
Called after a getNamespaceDescriptor request has been processed.
@param ctx the environment to interact with the framework and master
@param ns  the NamespaceDescriptor
hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MasterObserver.java