def serialized(self):
        to_ret = {}
        for group, requirements in self.items():
            to_ret[group] = [str(requirement) for requirement in requirements]
        return to_ret
def inc_c(self, ind):
        r, c = self.row_col(ind)
        c += 1
        if c == self.nc:
            c = 0
        if r == (self.nr - 1) and c == (self.nc - 1):
            c = 0
        return self.indx(r, c)