class Test

	def main
		.test1
		.test2
		
	def test1
		# Invoke a method in an extension of a generic, ancestor interface.
		# In this case, the class is Dictionary<of TKey, TValue>.KeyCollection
		# and the extension method is declared on IEnumerable<of TKey> which KeyCollection implements.

		# Then do it again for Dictionary<of TKey, TValue>.ValueCollection
		# Note that it implement IEnumerable<of TValue> which is using the *2nd* generic parameter, not the first.
		d = {'x': 1, 'y': 1}

		for key in d.keys.toList.sorted
			assert key in ['x', 'y']
		assert (for key in d.keys.toList.sorted get key) == ['x', 'y']

		for value in d.values.toList
			assert value == 1
		assert (for value in d.values.toList get value) == [1, 1]

	def test2
		x = X()
		.takeEnum(x)
		y = x.toList  # previously broken. Cobra would not find the extension method.
		assert y == List<of int>(x)
		assert y == [1, 2, 3]

	def takeEnum(e as IEnumerable<of int>)
		assert e.toList is not e
		assert e.toList == List<of int>(e)


class X implements IEnumerable<of int>

	def getEnumerator as IEnumerator<of int>
		return [1, 2, 3].getEnumerator

	def getEnumerator as System.Collections.IEnumerator
		implements System.Collections.IEnumerable
		return .getEnumerator