text: // Copyright (c) 2019 Uber Technologies, Inc.
  //
  // 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.
  
  export class XVIZBaseWriter {
    constructor(sink) {
      if (!sink) {
        throw new Error('Writer must be provided a sink');
      }
  
      this.sink = sink;
    }
  
    _checkValid() {
      if (!this.sink) {
        throw new Error('Cannot use this Writer after "close()" has been called.');
      }
    }
  
    close() {
      if (this.sink) {
        this.sink.close();
        this.sink = null;
      }
    }
  }
  