def add_cons_vars(self, what, **kwargs):
add_cons_vars_to_problem(self, what, **kwargs)<EOL>
Add constraints and variables to the model's mathematical problem.

        Useful for variables and constraints that can not be expressed with
        reactions and simple lower and upper bounds.

        Additions are reversed upon exit if the model itself is used as
        context.

        Parameters
        ----------
        what : list or tuple of optlang variables or constraints.
           The variables or constraints to add to the model. Must be of
           class `optlang.interface.Variable` or
           `optlang.interface.Constraint`.
        **kwargs : keyword arguments
           Passed to solver.add()