         k.expects("my_method")
     ).should.throw("'my_method' is not an existing method; you can only mock existing methods on objects (or classes) not passed in by mock()")      
       
-  it "throws an error if method_name does not already exist on an object that was not passed in by mock()", ->
+  it "throws an error if method_name does not already exist on an instance that was not passed in by mock()", ->
     o = new Object()
     o.some_method = "some method"
     (->

        o.expects("my_method")
    ).should.throw("Object object has no method 'expects'")
  
  it "adds method_name to mock objects passed in by mock()", ->
    mock (m) ->
      m.expects("my_method")
      (typeof m.my_method).should.equal('function')

      o.my_method.should.not.equal(existing_method)
      o.my_method()                 # otherwise we'll get a 'my_method not called' error
      
  it "throws an error if method_name does not already exist on an instance that was not passed in by mock()", ->
    class Klass
      some_method: -> "some method"
    k = new Klass()
