IterationInfo createIterationInfo(SpockExecutionContext context, int iterationIndex, Object[] args, int estimatedNumIterations) {
    FeatureInfo currentFeature = context.getCurrentFeature();
    Object[] dataValues = copyOfRange(args, 0, currentFeature.getDataVariables().size());
    IterationInfo result = new IterationInfo(currentFeature, iterationIndex, dataValues, estimatedNumIterations);
    result.setName(currentFeature.getName());
    String iterationName = currentFeature.getIterationNameProvider().getName(result);
    result.setDisplayName(iterationName);
    return result;
  }
Executes a single Spec. Notifies its supervisor about overall execution
progress and every invocation of Spec code.
Supervisor also determines the error strategy.

@author Peter Niederwieser
spock-core/src/main/java/org/spockframework/runtime/PlatformSpecRunner.java