Removed PageArgs.
Replaced with getSlug().
Removed PageArg class.
Start of capability validation.
Comments.
An attempt at a Capability enum.
Comments.
No longer abstract.
Changed back to abstract. Added isValid() method.
Comment.
Validating $capability before assigning it.
Comments.
First pass at menu icon validation.
Started update of page class documentation.
Updated error message.
Validating and setting $position.
Removing spaces.
Changed $parentSlug back to protected.
Moved setPosition() down.
Validating and setting $parentSlug.