private static CallSpecAndTarget[] GetCallsExpectedButNoReceived(IEnumerable <CallSpecAndTarget> expectedCalls, IEnumerable <ICall> receivedCalls)
 {
     return(DiffAlgorithm.DifferenceBetween(expectedCalls, receivedCalls, (call, spec) => Matches(spec, call)));
 }
 private static ICall[] GetCallsReceivedButNotExpected(IEnumerable <CallSpecAndTarget> expectedCalls, IEnumerable <ICall> receivedCalls)
 {
     return(DiffAlgorithm.DifferenceBetween(receivedCalls, expectedCalls, Matches));
 }