Verifying method called at least once with specific params

var calledArguments = new List<string>();
// set up calls to Log() to record arguments
Isolate.WhenCalled(() => logger.Log(null)).DoInstead(
    context => 
    {
        var argument = (string)context.Parameters[0];
        calledArguments.Add(argument);
    });

// call the method under test
var target = new Foo();
target.SomeMethod();

// assert that a specific argument has been received
bool result = Array.Exists(calledArguments.ToArray(), logLine => logLine.Contains("message with");
Assert.IsTrue(result);

Isolate.WhenCalled((string m) => logger.Error(m))
  .AndArgumentsMatch(m =>
  {
    if (m.Contains("substring I'm looking for"))
    {
      actualMessage = m;
      return true;
    }
    else
    {
      return false;
    }
  })
  .IgnoreCall();

// Do the actual call...

// Cheat and use the saved message from the WhenCalled method
Isolate.Verify.WasCalledWithExactArguments(() => logger.Error(actualMessage));