code: @Override
      public void deleteGraph(URI graphUri) {
  
          if (graphUri == null || !this.canBeModified())
              return;
  
          // Use HTTP protocol if possible
          if (this.sparqlServiceEndpoint != null) {
              this.datasetAccessor.deleteModel(graphUri.toASCIIString());
          } else {
              deleteGraphSparqlUpdate(graphUri);
          }
  
          log.debug("Graph deleted: {}", graphUri.toASCIIString());
      }
docs: Delete a named model of a Dataset
  
  @param graphUri