code: private static Weight getWeight(int i, int j, Object v1, Object v2,
              DirectedGraph g, Weight[][] updatedEdges) {
          Weight w = updatedEdges[i][j];
          if (w == null) {
              Edge e = g.getEdge(v1, v2);
              if (e != null) {
                  w = e.getWeight();
              }
          }
          return w;
      }
docs: Gets the length of the edge between vertices <code>v1</code> and
  <code>v2</code>, either as originally specified in a directed graph or
  as updated by DPC.
  
  @param i
  index of <code>v1</code> in the vertex ordering.
  @param j
  index of <code>v2</code> in the vertex ordering.
  @param v1
  a vertex.
  @param v2
  a vertex.
  @param g
  a <code>DirectedGraph</code>.
  @param updatedEdges
  a matrix of updates to the edge lengths as computed by DPC.
  @return a <code>Weight</code> representing the length of the specified
  edge, or <code>null</code> if no edge exists between
  <code>v1</code> and <code>v2</code>.