public GraphTraversal<Edge, Edge> mergeE(final GValue<Map<?, Object>> searchCreate) {
        final GraphTraversalSource clone = GraphTraversalSource.this.clone();
        clone.gremlinLang.addStep(GraphTraversal.Symbols.mergeE, searchCreate);
        final GraphTraversal.Admin<Edge, Edge> traversal = new DefaultGraphTraversal<>(clone);
        return traversal.addStep(new MergeEdgeStep(traversal, true, searchCreate));
    }
Spawns a {@link GraphTraversal} by doing a merge (i.e. upsert) style operation for an {@link Edge} using a
{@code Map} as an argument.

@param searchCreate This {@code Map} can have a key of {@link T} {@link Direction} or a {@code String}.
@since 4.0.0
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversalSource.java