anchor.diff:  [source, java]
   ----
   class BothOptionAndParametersMandatory {
  -    @Parameters(arity = "1..*", descriptions = "at least one File")
  +    @Parameters(arity = "1..*", description = "at least one File")
       File[] files;
   
       @Option(names = "-n", required = true, description = "mandatory number")
  
positive.code: [source, java]
  ----
  class ArityDemo {
      @Parameters(arity = "1..3", descriptions = "one to three Files")
      File[] files;
  
      @Option(names = "-f", arity = "2", description = "exactly two floating point numbers")
  
negative.code: import java.io.File;
  
  class Convert {
      @Option(names = "-patterns", description = "the regex patterns to use")
      Pattern[] patterns;
  
      @Parameters(/* type = File.class, */ description = "the files to convert")
  