How to convert MethodCallExpression to BinaryExpression

I've created a MethodCallExpression that calls a function which returns a bool. My problem is to convert the MethodCallExpression somehow into a BinaryExpression.

Or otherwise stated, how can i c开发者_JS百科onstruct this expression by hand:

Expression<Func<string, bool>> exp = x => x.Contains("test");

Problem solved, see comments