@Beta
  default void executionStart(ISpockExecution spockExecution) {}
Is called right before Spock starts executing tests.
<p>
Extensions get access to the {@link IStore} via the {@link ISpockExecution}
and can initialize things that are needed during execution.
@since 2.4
spock-core/src/main/java/org/spockframework/runtime/extension/IGlobalExtension.java