arangosh> var examples = require("org/arangodb/graph-examples/example-graph.js");
arangosh> var graph = examples.loadGraph("social");
arangosh> var query = graph._vertices({name: "Alice"});
arangosh> query.edges().vertices().restrict(["female", "male", "products"]).toArray();
[ArangoError 10: vertex collections: products are not known to the graph]