default void preModifyNamespace(final ObserverContext<MasterCoprocessorEnvironment> ctx,
    NamespaceDescriptor currentNsDescriptor, NamespaceDescriptor newNsDescriptor)
    throws IOException {
  }
Called prior to modifying a namespace's properties.
@param ctx                 the environment to interact with the framework and master
@param currentNsDescriptor current NamespaceDescriptor of the namespace
@param newNsDescriptor     after modify operation, namespace will have this descriptor
hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MasterObserver.java