import { UISpan } from '../types';
/** Minimal span fields required for building the hierarchical timeline tree. */
type TimelineSpan = {
    spanId: string;
    name: string;
    spanType: string;
    startedAt: Date | string;
    endedAt?: Date | string | null;
    parentSpanId?: string | null;
};
/**
 * When `anchorSpanId` is provided, that span is treated as the displayed root
 * regardless of its `parentSpanId` -- the branch-subtree case from `getBranch`,
 * where the anchor has a real parent that's outside the returned set. Without
 * it, the displayed roots are the spans with no parent (the trace case).
 */
export declare const formatHierarchicalSpans: (spans: TimelineSpan[], anchorSpanId?: string) => UISpan[];
export {};
