public void setBranchTraversal(final Traversal.Admin<S, M> branchTraversal) {
        this.branchTraversal = this.integrateChild(branchTraversal);
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
@author Daniel Kuppitz (http://gremlin.guru)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/branch/BranchStep.java