Looking for examples of how to use IExpression to obtain method information

Hi,

I'm looking for examples on how I can get information about the methods being called, simple in the following method I would like to be able to determine the type, name & the return type of the method Return on the Observable class.

static void Main(string[] args)

    {
        Observable.Return(42);
    }

protected override void Run(IExpression element, ElementProblemAnalyzerData data, IHighlightingConsumer consumer)
{
     // What goes here....
}