anchor.diff:  will be used, or if there is none, then the preference is removed and
   the default is used.
   
  +===== `colors`
  +
  +Set the shell’s use of colors.
  +
  +Default is `true`.
  +
   [[GroovyShell-show-last-result]]
   ===== `show-last-result`
   
  
positive.code: 
  [[GroovyShell-RecognizedPreferences]]
  ==== Recognized Preferences
  
  [[GroovyShell-verbosity]]
  ===== `verbosity`
  
negative.code: 
  [[GroovyShell-GMavenPlus]]
  == GMavenPlus Maven Plugin
  https://github.com/groovy/GMavenPlus[GMavenPlus] is a Maven plugin with goals
  that support launching a Groovy Shell or Groovy Console bound to a Maven
  project.
  
  