test_plugins.xml

<library path="test_plugins">
  <class name="test_pluginlib/foo" type="test_plugins::Foo" base_class_type="test_base::Fubar">
    <description>This is a foo plugin.</description>
  </class>
  <class name="test_pluginlib/bar" type="test_plugins::Bar" base_class_type="test_base::Fubar">
    <description>This is a bar plugin.</description>
  </class>
  <class name="test_pluginlib/none" type="test_plugins::None" base_class_type="test_base::Fubar">
    <description>This is a broken none plugin.</description>
  </class>
</library>