this.modelset.addStatement(stmt);
assertTrue(this.modelset.containsStatements(a, blankNode, RDF.type, RDF.Statement));
this.modelset.removeStatement(stmt);
assertFalse(this.modelset.containsStatements(a, blankNode, RDF.type, RDF.Statement));
Diff diff = new DiffImpl();
diff.addStatement(stmt);
this.modelset.update(diff);
assertTrue(this.modelset.containsStatements(a, blankNode, RDF.type, RDF.Statement));
diff = new DiffImpl();
diff.removeStatement(stmt);
this.modelset.update(diff);
assertFalse(this.modelset.containsStatements(a, blankNode, RDF.type, RDF.Statement));
}