public <S> GraphTraversal<S, S> inject(S... starts) {
        // a single null is [null]
        final S[] s = null == starts ? (S[]) new Object[] { null } : starts;
        final GraphTraversalSource clone = this.clone();
        clone.gremlinLang.addStep(GraphTraversal.Symbols.inject, s);
        final GraphTraversal.Admin<S, S> traversal = new DefaultGraphTraversal<>(clone);
        return traversal.addStep(new InjectStep<S>(traversal, s));
    }
Spawns a {@link GraphTraversal} starting it with arbitrary values.
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversalSource.java