}
			c := b.Preds[0].Block()
			d := b.Preds[1].Block()

			// Find their common predecessor block (the one that branches based on wb on/off).
			// It might be a diamond pattern, or one of the blocks in the diamond pattern might
			// be missing.
			var decisionBlock *ssa.Block
			if len(c.Preds) == 1 && c.Preds[0].Block() == d {
				decisionBlock = d

	// mailbox = name-addr / addr-spec
	// group = display-name ":" [group-list] ";" [CFWS]

	// addr-spec has a more restricted grammar than name-addr,
	// so try parsing it first, and fallback to name-addr.
	// TODO(dsymonds): Is this really correct?
	spec, err := p.consumeAddrSpec()
	if err == nil {
		var displayName string
		p.skipSpace()
		if !p.empty() && p.peek() == '(' {
			displayName, err = p.consumeDisplayNameComment()

   * |      |
   * e ---- c ---- f
   * }</pre>
   */
  private static final SuccessorsFunction<Character> JAVADOC_GRAPH =
      createUndirectedGraph("ba", "ad", "be", "ac", "ec", "cf");

  /**
   * A diamond shaped directed graph (arrows going down):
   *
   * <pre>{@code
   *   a
   *  / \
   * b   c
   *  \ /
   *   d
   * }</pre>
   */
  private static final SuccessorsFunction<Character> DIAMOND_GRAPH =

   * |      |
   * e ---- c ---- f
   * }</pre>
   */
  private static final SuccessorsFunction<Character> JAVADOC_GRAPH =
      createUndirectedGraph("ba", "ad", "be", "ac", "ec", "cf");

  /**
   * A diamond shaped directed graph (arrows going down):
   *
   * <pre>{@code
   *   a
   *  / \
   * b   c
   *  \ /
   *   d
   * }</pre>
   */
  private static final SuccessorsFunction<Character> DIAMOND_GRAPH =