For more control the dendropy method self.as_string('newick', **kwargs)
        can be used.
        KWargs include:
        suppress_internal_node_labels [True/False]
            - turn on/off bootstrap labels
        suppress_rooting [True/False]
            - turn on/off [&U] or [&R] rooting
              state labels
        edge_label_compose_func
            - function to convert edge lengths:
              takes edge as arg, returns string

def newick(self):
        """
        For more control the dendropy method self.as_string('newick', **kwargs)
        can be used.
        KWargs include:
        suppress_internal_node_labels [True/False]
            - turn on/off bootstrap labels
        suppress_rooting [True/False]
            - turn on/off [&U] or [&R] rooting
              state labels
        edge_label_compose_func
            - function to convert edge lengths:
              takes edge as arg, returns string
        """
        n = self._tree.as_string('newick',
                                 suppress_rooting=True,
                                 suppress_internal_node_labels=True)
        if n:
            return n.strip(';\n') + ';'
        return n