'Generates the next Gray code ordered subset.
Examples
>>> from sympy.combinatorics.subsets import Subset
>>> a = Subset([1, 2, 3], [1, 2, 3, 4])
>>> a.next_gray().subset
[1, 3]
See Also
iterate_graycode, prev_gray'

def next_gray(self):

    return self.iterate_graycode(1)
