@Override
        public default SparqlTraversal<S, E> iterate() {
            return SparqlTraversal.super.iterate();
        }
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