} else if (state == DfsState.VISITING) {
                    // we are already visiting this vertex, this mean we have a cycle
                    int pos = cycle.lastIndexOf(v);
                    List<String> ret = cycle.subList(pos, cycle.size());
                    ret.add(v);
                    return ret;
                }
            }
        }
        return null;
    }

            } else if (state == DfsState.VISITING) {
                // we are already visiting this vertex, this mean we have a cycle
                int pos = cycle.lastIndexOf(v.label);
                List<String> ret = cycle.subList(pos, cycle.size());
                ret.add(v.label);
                return ret;
            }
        }
        return null;
    }

    static class Vertex {

reader; protected String inputEncoding; protected int bufLoadFactor; protected char[] buf; protected int bufSoftLimit; protected boolean preventBufferCompact; protected int bufAbsoluteStart; protected int bufStart; protected int bufEnd; protected int pos; protected int posStart; protected int posEnd; protected char[] pc; protected int pcStart; protected int pcEnd; protected boolean usePC; protected boolean seenStartTag; protected boolean seenEndTag; protected boolean pastEndTag; protected boolean seenAmpersand;...