Add possibility to skip setting methods

If we mock interface and we have 


  interface Example {
    public function mockedMethod();
    public function skippedForMockMethod();
  }

$this->mock('Example)->mockedMethod()->new();

This will couse fatal exception:

contains 1 abstract method and must therefore be declared abstract or implement the remaining methods.

I don't think this is something what we expect, to decleare all the methods if we require only one for the test this is redundant.

So this is my proposition but i have 4 days experience with testing. So maybe there is better solution for example. Two methods.

$this->mock('Example'); // works as current
$this->mockParial('Example'); // works as poroposed, skip the setMethods.