2. State A has accepted the jurisdiction of the International Court of Justice (ICJ) in a unilateral declaration pursuant to Article 36(2) of the ICJ's Statute. The declaration, however, contains the following provision: "This declaration shall not apply to disputes with regard to matters which are essentially within the domestic jurisdiction of State A as determined by State A." (a) Is this provision valid? (b) In a suit between State A and State B, may State B invoke this provision as to matters it considers within its own domestic jurisdiction? Explain