[tree covering most of tree reader code
comment contains [extra brackets] inside comment
]
(
        (s1:0.2, s2:0.4):0.6,
        (
                s3
                :
                0.3
                ,
                's 4':0.1):0.1,
        (s5:0.02, "s-6":0.04):0.06
):0.2;