import {
  IRunArgs,
  OccurrenceGeneratorRunResult,
  Operator,
  OperatorFnOutput,
} from '../occurrence-generator';
/**
 * An operator function which deduplicates an occurrence stream. Occurrence
 * `duration` is currently ignored.
 */
export declare function unique(): OperatorFnOutput;
export declare class UniqueOperator extends Operator {
  /** Not actually used but necessary for IRunnable interface */
  set(_: 'timezone', value: string | null): UniqueOperator;
  _run(args?: IRunArgs): OccurrenceGeneratorRunResult;
  protected calculateIsInfinite(): boolean;
  protected calculateHasDuration(): boolean;
}