'Returns trees.
Trees are actually an array of JsonDicts. It\'s usually one tree, except in the case of Nexus'

def get_data(self, tree_index=0):

    file_ext = self.original_dataset.datatype.file_ext
    file_name = self.original_dataset.file_name
    parseMsg = None
    jsonDicts = []
    rval = {'dataset_type': self.dataset_type}
    if (file_ext == 'nhx'):
        newickParser = Newick_Parser()
        (jsonDicts, parseMsg) = newickParser.parseFile(file_name)
    elif (file_ext == 'phyloxml'):
        phyloxmlParser = Phyloxml_Parser()
        (jsonDicts, parseMsg) = phyloxmlParser.parseFile(file_name)
    elif (file_ext == 'nex'):
        nexusParser = Nexus_Parser()
        (jsonDicts, parseMsg) = nexusParser.parseFile(file_name)
        jsonDicts = jsonDicts[int(tree_index)]
        rval['trees'] = parseMsg
    rval['data'] = jsonDicts
    rval['msg'] = parseMsg
    return rval
