public static ApiClientHeaderProvider.Builder defaultHttpJsonApiClientHeaderProviderBuilder() {
    return ApiClientHeaderProvider.newBuilder()
        .setGeneratedLibToken(
            "gapic", GaxProperties.getLibraryVersion(ExecutionsStubSettings.class))
        .setTransportToken(
            GaxHttpJsonProperties.getHttpJsonTokenName(),
            GaxHttpJsonProperties.getHttpJsonVersion());
  }
Returns a builder for the default REST ChannelProvider for this service.
java-workflow-executions/google-cloud-workflow-executions/src/main/java/com/google/cloud/workflows/executions/v1/stub/ExecutionsStubSettings.java