Operator
There is a OperatorManager trait and a simple implementation of it in the form of a Substrate pallet called Operator. The OperatorManager trait defines two methods: is_operator and set_owner. The Operator pallet implements these methods to keep track of an account that is designated as an operator and allow for ownership changes.
The Operator pallet has a configuration trait Config that extends frame_system::Config. It defines an event type Event and a constant type InitialOwner which specifies the initial owner of the pallet.
The Operator pallet has two storage items: Operator and Owner. Operator stores the account ID of the designated operator and Owner stores the account ID of the current owner.
The Operator pallet defines a check_owner function to verify that the origin (i.e., the sender) of a transaction is the current owner of the pallet. It also defines a set_operator function that allows the owner to set the designated operator account. The set_operator function modifies the Operator storage item and emits an OperatorChanged event.
Finally, the Operator pallet implements the OperatorManager trait to provide implementations for the is_operator and set_owner methods. The is_operator method returns whether a given account is the designated operator account. The set_owner method allows for the owner of the pallet to change. This method modifies the Owner storage item and emits an OwnerChanged event.