anchor.diff:  }
   ----
   
  -[source,java]
  +.Kotlin
  +[source,kotlin,role="secondary"]
  +----
  +import java.util.Locale
  +import javax.crypto.Cipher
  +// ...
  +
  +class App {
  +    @Parameters
  +    lateinit var locale: Locale
  +
  +    @Option(names = ["-a"])
  +    lateinit var cipher: Cipher
  +}
  +----
  +
  +.Java
  +[source,kotlin,role="primary"]
   ----
   App app = new App();
   CommandLine commandLine = new CommandLine(app)
  
positive.code: }
  ----
  
  === Enum Types
  It is encouraged to use `enum` types for options or positional parameters with a limited set of valid values.
  Not only will picocli validate the input, it allows you to <<Show Default Values,show all values>> in the usage help message with `@Option(description = "Valid values: ${COMPLETION-CANDIDATES}")`. It also allows command line completion to suggest completion candidates for the values of this option.
  
  Enum value matching is case-sensitive by default, but from 3.4 this can be controlled with `CommandLine::setCaseInsensitiveEnumValuesAllowed` and `CommandSpec::caseInsensitiveEnumValuesAllowed`.
  
  == Default Values
  It is possible to define a default value for an option or positional parameter, that is assigned when the user did not specify this option or positional parameter on the command line.
  
negative.code: 
  class LoggingMixin {
      @Spec(Spec.Target.MIXEE)
      private lateinit var mixee: CommandSpec// spec of the command where the @Mixin is used
      var verbosity = BooleanArray(0)
  
      /**
  