In contrast, in Germany, the relation between individual employees and employers is considered to be asymmetrical. In consequence, many working conditions are not negotiable due to a strong legal protection of individuals. However, the German flavor or works legislation has as its main objective to create a balance of power between employees organized in unions and employers organized in employers associations. This allows much wider legal boundaries for collective bargaining, compared to the narrow boundaries for individual negotiations. As a condition to obtain the legal status of a trade union, employee associations need to prove that their leverage is strong enough to serve as a counterforce in negotiations with employers. If such an employees association is competing against another union, its leverage may be questioned by unions and then evaluated in a court trial. In Germany, only very few professional associations obtained the right to negotiate salaries and working conditions for their members, notably the medical doctors association Marburger Bund and the pilots association Vereinigung Cockpit. The engineers association Verein Deutscher Ingenieure does not strive to act as a union, as it also represents the interests of engineering businesses.