'Returns the smallest representable number larger than a.
>>> c = ExtendedContext.copy()
>>> c.Emin = -999
>>> c.Emax = 999
>>> ExtendedContext.next_plus(Decimal(\'1\'))
Decimal(\'1.00000001\')
>>> c.next_plus(Decimal(\'-1E-1007\'))
Decimal(\'-0E-1007\')
>>> ExtendedContext.next_plus(Decimal(\'-1.00000003\'))
Decimal(\'-1.00000002\')
>>> c.next_plus(Decimal(\'-Infinity\'))
Decimal(\'-9.99999999E+999\')
>>> c.next_plus(1)
Decimal(\'1.00000001\')'

def next_plus(self, a):

    a = _convert_other(a, raiseit=True)
    return a.next_plus(context=self)
