'Return a tuple of sets (ProductSets) input of the self.
Examples
>>> from sympy import Interval, ComplexRegion, Union
>>> a = Interval(2, 3)
>>> b = Interval(4, 5)
>>> c = Interval(1, 7)
>>> C1 = ComplexRegion(a*b)
>>> C1.psets
(Interval(2, 3) x Interval(4, 5),)
>>> C2 = ComplexRegion(Union(a*b, b*c))
>>> C2.psets
(Interval(2, 3) x Interval(4, 5), Interval(4, 5) x Interval(1, 7))'

@property
def psets(self):

    if self.sets.is_ProductSet:
        psets = ()
        psets = (psets + (self.sets,))
    else:
        psets = self.sets.args
    return psets
