73The argument that the merchants were entitled to discontinue their contractual relations with BG at any time has no force since the right to terminate a contract in no way prevents its actual application until such time as the right to terminate it has been exercised. It should be observed that an undertaking in a dominant position is powerful enough to require its customers not only to enter into such contracts but also to maintain them, with the result that the legal possibility of termination is in fact rendered illusory.