How to use the elasticsearch.errors.ConnectionFault function in elasticsearch

it('should return a boom 503 server timeout error for ES connection errors', function () {
    expect(handleESError(new esErrors.ConnectionFault()).output.statusCode).to.be(503);
    expect(handleESError(new esErrors.ServiceUnavailable()).output.statusCode).to.be(503);
    expect(handleESError(new esErrors.NoConnections()).output.statusCode).to.be(503);
    expect(handleESError(new esErrors.RequestTimeout()).output.statusCode).to.be(503);
  });

it('should return a boom 503 server timeout error for ES connection errors', function () {
    expect(handleESError(new esErrors.ConnectionFault()).output.statusCode).to.be(503);
    expect(handleESError(new esErrors.ServiceUnavailable()).output.statusCode).to.be(503);
    expect(handleESError(new esErrors.NoConnections()).output.statusCode).to.be(503);
    expect(handleESError(new esErrors.RequestTimeout()).output.statusCode).to.be(503);
  });

it('makes es.ConnectionFault a SavedObjectsClient/EsUnavailable error', () => {
    const error = new esErrors.ConnectionFault();
    expect(isEsUnavailableError(error)).to.be(false);
    expect(decorateEsError(error)).to.be(error);
    expect(isEsUnavailableError(error)).to.be(true);
  });

it('should return a boom 503 server timeout error for ES connection errors', function () {
    expect(handleESError(new esErrors.ConnectionFault()).output.statusCode).to.be(503);
    expect(handleESError(new esErrors.ServiceUnavailable()).output.statusCode).to.be(503);
    expect(handleESError(new esErrors.NoConnections()).output.statusCode).to.be(503);
    expect(handleESError(new esErrors.RequestTimeout()).output.statusCode).to.be(503);
  });

it('handles ConnectionFault', () => {
    const err = new errors.ConnectionFault();
    expect(isKnownError(err)).to.be(true);

    const wrappedErr = handleKnownError(err);
    expect(wrappedErr.message).to.be(
      'Connection Failure: ' +
      'Check the Elasticsearch Monitoring cluster network connection and refer to the Kibana logs for more information.'
    );
    expect(wrappedErr.isBoom).to.be(true);
    expect(wrappedErr.isServer).to.be(true);
    expect(wrappedErr.data).to.be(null);
    expect(wrappedErr.output).to.eql({
      statusCode: 503,
      payload: {
        statusCode: 503,
        error: 'Service Unavailable',
        message: (