} else if(isExistingGraphName(name,Symbols.Graph)){
ModelGraph mg = getModelGraph(name, false, false);
mg.delete();
removeFromIndex( name, Symbols.Graph );
} else if (name.equals(defaultGraphName)){
throw new EntityUndeletableException(defaultGraphName);
}
//delete the graph from the initModels list
syncModels.remove(name);
} finally {
datasetLock.writeLock().unlock();