@Override public String graph() throws Exception {
  StringBuffer text=new StringBuffer();
  text.append("digraph CobwebTree {\n");
  m_cobwebTree.graphTree(text);
  text.append("}\n");
  return text.toString();
}

@ Override public String graph ( ) throws Exception { StringBuffer text = new StringBuffer ( ) ; text . append ( "digraph CobwebTree {\n" ) ; m_cobwebTree . graphTree ( text ) ; text . append ( "}\n" ) ; return text . toString ( ) ; }
generates the graph string of the cobweb tree
