anchor.diff:  
   The following source tree contains Java and Kotlin source files. Java source files live in `src/main/java`, whereas Kotlin source files live in `src/main/kotlin`.
   
  +====
  +[.multi-language-sample]
  +=====
  +[source,groovy]
   ----
   .
   ├── build.gradle
  
positive.code: Any code under `buildSrc` should use a package similar to application code.
  Optionally, the `buildSrc` directory can host a build script if additional configuration is needed (e.g. to apply plugins or to declare dependencies).
  
  ----
  .
  ├── build.gradle
  
negative.code:         └── java
              └── StringUtilsTest.java
  ----
  =====
  [.multi-language-sample]
  =====
  [source,kotlin]
  ----
  .
  ├── build.gradle.kts
  ├── gradle
  │   └── integration-test.gradle.kts
  ├── settings.gradle.kts
  └── src
      ├── integTest
      │   └── java
      │       └── DefaultFileReaderIntegrationTest.java
      ├── main
      │   └── java
      │       ├── DefaultFileReader.java
      │       ├── FileReader.java
      │       └── StringUtils.java
      └── test
          └── java
              └── StringUtilsTest.java
  ----
  =====
  ====
  
  Gradle models source code directories with the help of the <<building_java_projects.adoc#sec:java_source_sets,source set concept>>.
  By pointing an instance of a source set to one or many source code directories, Gradle will automatically create a corresponding compilation task out-of-the-box.
  