public DumpQueryExecutor(Model m, String propertyUri, boolean ngramIndex,int minGram, int maxGram){
loaded = true;
this.propertyUri = propertyUri;
Dataset ds1 = DatasetFactory.createMem();
EntityDefinition entDef = new EntityDefinition("uri", "text",m.getResource(propertyUri)) ;
// Lucene, in memory.
Directory dir = new RAMDirectory();
// Join together into a dataset