for a task, that is it is public, non-abstract, has a no-arg
constructor and a public no-arg execute method.
PR: 4163
Submitted by: Ralf Wiebicke <ralf@rw7.de>
git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269857 13f79535-47bb-0310-9956-ffa450edef68