true private attributes for Moose/Moo/Mouse

 Lexical::Accessor generates coderefs which can be used as methods to
 access private attributes for objects.
 .
 The private attributes are stored inside-out, and do not add any
 accessors to the class' namespace, so are completely invisible to any
 outside code, including any subclasses. This gives your attribute
 complete privacy: subclasses can define a private (or even public)
 attribute with the same name as your private one and they will not
 interfere with each other.