public Object initialValue(final String sideEffectKey) {
        for (Triplet<String, Supplier, BinaryOperator> triplet : sideEffects) {
            if (triplet.getValue0().equals(sideEffectKey)) {
                return triplet.getValue1().get();
            }
        }
        return null;
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/strategy/decoration/SideEffectStrategy.java