code: protected void removeIndex( IndexDefinition oldDefn,
                                  ManagedIndex existingIndex,
                                  String workspaceName ) {
          logger().debug("Index provider '{0}' is removing index in workspace '{1}': {2}", getName(), workspaceName, oldDefn);
          existingIndex.shutdown(true);
      }
docs: Method called when this provider needs to remove an existing index given the unique pair of workspace name and index
  definition. An index definition can apply to multiple workspaces, and when it does this method will be called once for each
  applicable workspace.
  <p>
  The default implementation is to simply delegate the call to a specific index's
  {@link org.modeshape.jcr.spi.index.provider.ProvidedIndex#shutdown(boolean)} method, indicating that the index should be destroyed.
  </p>
  
  @param oldDefn the previous definition of the index; never null
  @param existingIndex the existing index prior to this update, as returned from {@link #createIndex} or {@link #updateIndex}
  ; never null
  @param workspaceName the name of the actual workspace to which the new index applies; never null