Problem provided data.

        variables = {variable-name: list-of-domain-values}
        constraints = [(constraint_function, variable-names, variable-default-values)]

def set_conditions(self, variables, constraints):
        """Problem provided data.

        variables = {variable-name: list-of-domain-values}
        constraints = [(constraint_function, variable-names, variable-default-values)]
        """
        self._vars, self._constraints = variables, []
        self._constraints_for_var = {}
        vars_constraint_count = {}
        # build constraint objects
        for func, variables, values in constraints:
            c = Constraint(func, variables, values, self._compute_search_spaces(variables))
            self._constraints.append(c)
            for var in variables:
                self._constraints_for_var[var] = self._constraints_for_var.get(var, []) + [c]
                vars_constraint_count[var] = vars_constraint_count.get(var, 0) + 1
        # sort into most constraining first
        self._constraints.sort()

        self._variable_expand_order = tuple(sorted(self._vars.keys(), key=vars_constraint_count.get, reverse=True))