bug663.scala:11: error: name clash between defined and inherited member:
method asMatch:(m: Test.this.Node)Any and
method asMatch:(node: Test.this.Matchable)Any in trait MatchableImpl
have same type after erasure: (m: test.Test#NodeImpl)java.lang.Object
    def asMatch(m : Node) : Any = {
        ^
one error found
