@staticmethod
def get_kktsolver_opt(solver_opts):
    """Returns the KKT solver selected by the user.

        Removes the KKT solver from solver_opts.

        Parameters
        ----------
        solver_opts : dict
            Additional arguments for the solver.

        Returns
        -------
        str or None
            The KKT solver chosen by the user.
        """
    if 'kktsolver' in solver_opts:
        kktsolver = solver_opts['kktsolver']
        del solver_opts['kktsolver']
    else:
        kktsolver = 'chol'
    return kktsolver
