Preload label

The "preload" directive specifies a string label to pass to a project configuration plugin function, called test_preload(). The original use was to enable a different Python version to be used for different tests, such as Python 2 versus Python 3.

The syntax is

#VVT: preload : somelabel

The only allowed attributes are the common ones: "testname", "parameters", "platform", and "option".