public static AdjacentToIncidentStrategy instance() {
        return INSTANCE;
    }
Optimizes the given step if possible. Basically this method converts <code>.out()</code> to <code>.outE()</code>
and <code>.values()</code> to <code>.properties()</code>.

@param traversal the traversal that holds the given step
@param step      the step to replace
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/strategy/optimization/AdjacentToIncidentStrategy.java