/**
 * Represents the persisted state of an entity.
 *
 * @remarks
 * This interface provides methods for getting and setting entity state during operation execution.
 * Setting state to null or undefined will delete the entity state.
 */
export interface TaskEntityState {
    /**
     * Gets a value indicating whether this entity currently has state.
     *
     * @returns true if the entity has state; false if the entity has not been initialized or was deleted.
     */
    readonly hasState: boolean;
    /**
     * Gets the current state of the entity.
     *
     * @typeParam T - The type to retrieve the state as.
     * @param defaultValue - Optional default value to return if no state is present.
     * @returns The entity state, or the default value if no state is present.
     *
     * @remarks
     * If no state is present, the defaultValue will be returned but it will NOT be persisted.
     * You must call setState() to persist state changes.
     */
    getState<T>(defaultValue?: T): T | undefined;
    /**
     * Sets the entity state.
     *
     * @param state - The state to set. Setting null or undefined will delete the entity state.
     *
     * @remarks
     * Setting state to null or undefined will effectively delete the entity.
     * The state will be serialized to JSON for persistence.
     */
    setState(state: unknown): void;
}