def gsea_cls_parser(cls):
    """Extact class(phenotype) name from .cls file.
    
    :param cls: the .cls file where located inside edb folder.
    :return: phenotype name and a list of class vector. 
    """
    
    with open(cls) as cls:
        file = cls.readlines()
    sample_name = file[1].strip('\n').split(" ")        
    classes = file[2].strip('\n').split(" ")
    phenoPos = sample_name[1]
    phenoNeg = sample_name[2]
    
    return phenoPos,phenoNeg,classes