'Internal version of format with cached results.
Returns
tuple
(equality constraints, inequality constraints)'

@pu.lazyprop
def __format(self):

    eq_constr = []
    if (self.noncvx_var != self.lin_op):
        eq_constr += lu.create_eq(self.lin_op, self.noncvx_var)
    return (eq_constr, [])
