/**
 * Copyright 2015 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { HeaderGetter, HeaderSetter, SpanContext } from './index';
export declare function parseContextFromHeader(str: string | string[] | undefined): SpanContext | null;
export declare function serializeSpanContext(spanContext: SpanContext): string;
export declare function extract(getter: HeaderGetter): SpanContext | null;
export declare function inject(setter: HeaderSetter, spanContext: SpanContext): void;
export declare function generate(): SpanContext;