@Override
    public void setup(final Memory memory) {
        memory.set(TELEPORTATION_ENERGY, null == this.initialRankTraversal ? 1.0d : 0.0d);
        memory.set(VERTEX_COUNT, 0.0d);
        memory.set(CONVERGENCE_ERROR, 1.0d);
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/computer/ranking/pagerank/PageRankVertexProgram.java