MoveVisibility
The visibility modifier describes which modules can access this module member.
By default, a module member can be called only within the same module.
enum MoveVisibility {
  PUBLIC
  PRIVATE
  FRIEND
}
Values
MoveVisibility.PUBLIC
A public member can be accessed by any module.
MoveVisibility.PRIVATE
A private member can be accessed in the module it is defined in.
MoveVisibility.FRIEND
A friend member can be accessed in the module it is defined in and any other module in its package that is explicitly specified in its friend list.
Member Of
MoveFunction  object