def __init__(self, groups=None):
        super(GroupedRequirements, self).__init__(NamedRequirements)
        self.groups = groups or self.default_groups
        self.filename = None
        self.create_default_groups()
def get_probabilities(self):
        """!
        @brief Returns 2-dimensional list with belong probability of each object from data to cluster correspondingly,
                where that first index is for cluster and the second is for point.