Add simple annotation processor for tests

libraries/examples/annotation-processor-example/src/main/kotlin/example/ExampleAnnotation.kt

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+package example
+
+import java.lang.annotation.ElementType
+import java.lang.annotation.Target
+
+annotation public class ExampleAnnotation

libraries/examples/annotation-processor-example/src/main/kotlin/example/ExampleAnnotationProcessor.kt

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+package example
+
+import javax.annotation.processing.AbstractProcessor
+import javax.annotation.processing.RoundEnvironment
+import javax.lang.model.SourceVersion
+import javax.lang.model.element.ElementKind
+import javax.lang.model.element.TypeElement
+import javax.tools.Diagnostic
+
+public class ExampleAnnotationProcessor : AbstractProcessor() {
+
+    private companion object {
+        val ANNOTATION_FQ_NAME = javaClass<ExampleAnnotation>().getCanonicalName()
+    }
+
+    override fun process(annotations: MutableSet<out TypeElement>?, roundEnv: RoundEnvironment): Boolean {
+        val elements = roundEnv.getElementsAnnotatedWith(javaClass<ExampleAnnotation>())
+
+        val elementUtils = processingEnv.getElementUtils()
+        val filer = processingEnv.getFiler()
+
+        for (element in elements) {
+            val packageName = elementUtils.getPackageOf(element).getQualifiedName().toString()
+            val className = element.getSimpleName().toString().capitalize() + "Generated"
+
+            filer.createSourceFile(className).openWriter().use { with(it) {
+                appendln("package $packageName;")
+                appendln()
+                appendln("public final class $className {}")
+            }}
+        }
+
+        return true;
+    }
+
+    override fun getSupportedSourceVersion() = SourceVersion.RELEASE_6
+
+    override fun getSupportedAnnotationTypes() = setOf(ANNOTATION_FQ_NAME)
+}

libraries/examples/annotation-processor-example/src/main/resources/META-INF/services/javax.annotation.processing.Processor

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+example.ExampleAnnotationProcessor