import { Observable } from 'rxjs';
import { BaseTreeControl } from './base-tree-control';
/** Nested tree control. Able to expand/collapse a subtree recursively for NestedNode type. */
export declare class NestedTreeControl<T> extends BaseTreeControl<T> {
    getChildren: (dataNode: T) => Observable<T[]>;
    /** Construct with nested tree function getChildren. */
    constructor(getChildren: (dataNode: T) => Observable<T[]>);
    /**
     * Expands all dataNodes in the tree.
     *
     * To make this working, the `dataNodes` variable of the TreeControl must be set to all root level
     * data nodes of the tree.
     */
    expandAll(): void;
    /** Gets a list of descendant dataNodes of a subtree rooted at given data node recursively. */
    getDescendants(dataNode: T): T[];
    /** A helper function to get descendants recursively. */
    private _getDescendants;
}