@JvmStatic fun subtypeOf(upperBound: TypeName): WildcardTypeName
Returns a type that represents an unknown type that extends bound. For example, if bound
is CharSequence.class, this returns ? extends CharSequence. If bound is Object.class,
this returns ?, which is shorthand for ? extends Object.
@JvmStatic fun subtypeOf(upperBound: Type): WildcardTypeName
@JvmStatic fun subtypeOf(upperBound: KClass<*>): WildcardTypeName