groovyCompilerClassLoader.allowPackage("groovy");
// Disallow classes from Groovy Jar that reference external classes. Such classes must be loaded from astTransformClassLoader,
// or a NoClassDefFoundError will occur. Essentially this is drawing a line between the Groovy compiler and the Groovy
// library, albeit only for selected classes that run a high risk of being statically referenced from a transform.
groovyCompilerClassLoader.disallowClass("groovy.util.GroovyTestCase");
groovyCompilerClassLoader.disallowClass("groovy.servlet.GroovyServlet");
// AST transforms need their own class loader that shares compiler classes with the compiler itself
final GroovyClassLoader astTransformClassLoader = new GroovyClassLoader(groovyCompilerClassLoader, null);
// can't delegate to compileClasspathLoader because this would result in ASTTransformation interface
// (which is implemented by the transform class) being loaded by compileClasspathClassLoader (which is