Stripping the type argument list, e.g. going fromjava.util.List to java.util.List is an unsafe cast.Wildcardingthe same type argument, e.g. going from java.util.List tojava.util.List, is safe. The latter type is writtenjava.util.List[_], or java.util.List[T] forSome type T, inScala. In both Java and Scala, this is anexistential type.As compiled with -Xlint:rawtypes -Xlint:unchecked: