drawEdges(debug) {
    let preprocessor = this.preprocessor,
        graph = preprocessor.graph,
        rings = preprocessor.rings,
        drawn = Array(this.preprocessor.graph.edges.length);
    drawn.fill(false);
    graph.traverseBF(0, vertex => {
      let edges = graph.getEdges(vertex.id);

      for (var i = 0; i < edges.length; i++) {
        let edgeId = edges[i];

        if (!drawn[edgeId]) {
          drawn[edgeId] = true;
          this.drawEdge(edgeId, debug);
        }
      }
    }); // Draw ring for implicitly defined aromatic rings

    if (!this.bridgedRing) {
      for (var i = 0; i < rings.length; i++) {
        let ring = rings[i]; //TODO: uses canvas ctx to draw... need to update this to SVG

        if (preprocessor.isRingAromatic(ring)) {
          this.drawAromaticityRing(ring);
        }
      }
    }
  }
Draw the actual edges as bonds.

@param {Boolean} debug A boolean indicating whether or not to draw debug helpers.