# this previously caused an uncaught exception in the compiler

class FooCollection implements IEnumerable<of Foo>

	var _nodes = Set<of Foo>()

	def getEnumerator as IEnumerator<of Foo>
		return _nodes.getEnumerator

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


class Foo

	var stuff = Set<of Object>()


class Program

	def main
		pass