anchor.diff:  ----
   
   === Programmatic Mixin
  -Picocli 3.0 introduces the concept of "mixins". Mixins are a convenient alternative to subclassing. Common options, common positional parameters or common usage help attributes can be defined in a separate class. This class can be reused in many other commands, either programmatically with the `CommandLine.addMixin` method, or declaratively with the `@Mixin` annotation.
  +Picocli 3.0 introduces the concept of "mixins". Mixins are a convenient alternative to subclassing. Common options, positional parameters or command attributes defined in a separate class can be reused in other commands, either programmatically with the `CommandLine.addMixin` method, or declaratively with the `@Mixin` annotation.
   
   The below example shows how a mixin can be added programmatically with the `CommandLine.addMixin` method:
   
  
positive.code: ----
  When using the `@Mixin` annotation, the command can reference the mixed-in object directly (for example, the `MyCommand` can reference its `myMixin` field to access the `ReusableOptions` object.
  
  Mixins added with the `@Mixin` annotation can also be accessed via the map returned by `CommandLine.getMixins`.
  
  
  === Reuse Combinations
  
  Mixins can be nested. There is no limitation to how deeply mixins can be nested. A mixin may also inherit options, positional parameters and command attributes from a super class.
  
  An option with the same name should not be defined multiple times or a `DuplicateOptionAnnotationsException` is thrown during initialization. Positional parameters for the same position may be defined multiple times, they can co-exist.
  
  
negative.code: assert mixin == commandLine.getMixins().get("myMixin");
  
  // the options defined in ReusableOptions have been added to the zip command
  commandLine.parse("-vvv");
  assert mixin.verbosity.length == 3;
  ----
  
  === `@Mixin` Annotation
  From picocli 3.0, a command can include a mixin by annotating a field with `@Mixin`. All picocli annotations found in the mixin class are added to the command that has a field annotated with `@Mixin`. For example:
  
  [source,java]
  ----
  