clearSearch() {
        this.batch();

        this.recurseDown(node => {
            // Reset search effects (show node, collapse, reset matched)
            node.show().collapse().state('matched', false);
        });

        if (this.config.selection.require) {
            this.previouslySelectedNodes().select();
        }

        this.end();

        return this;
    }
Clear nodes matched by previous search, restore all nodes and collapse parents.

@return {Tree} Tree instance.