title: How to get DS.find().then() to be called when using angular-data-mocks
body: <p>I've been trying to test a service I'm writing that makes use of angular-data data stores and can't get it to call the callback passed to <code>then()</code>. I've got a basic example of what I'm trying to do below and what I expect to happen.  Can anybody shed any light on what it is I'm doing wrong and why this doesn't work as expected?</p>
  
  <p>I'd expect this test to pass and print <code>this is called</code> to the console. It does neither, failing with "expected false to be true".</p>
  
  <pre><code>describe('usage of expectFind', function(){
      beforeEach(function (done) {
          inject(function (_DS_) {
              DS = _DS_;
              done();
          });
      });
  
      it('should call the callback passed to then', function(done){
          DS.expectFind('foo', 1).respond([{a: 'thing'}])
  
          var called = false;
          DS.find('foo', 1).then(function(aFoo){
              console.log('this is called');
              called = true;
              done();
          });
          expect(called).toBe(true);
      });
  });
  </code></pre>