@Override
        public default <E2> SparqlTraversal.Admin<S, E2> addStep(final Step<?, E2> step) {
            return (SparqlTraversal.Admin<S, E2>) Traversal.Admin.super.addStep((Step) step);
        }
The {@code SparqlTraversal} has no additional traversal steps. The only step available for "SPARQL" is the
{@link SparqlTraversalSource#sparql(String)} start step.

@author Stephen Mallette (http://stephen.genoprime.com)
sparql-gremlin/src/main/java/org/apache/tinkerpop/gremlin/sparql/process/traversal/dsl/sparql/SparqlTraversal.java