public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
    return EndpointServiceStubSettings.defaultGrpcApiClientHeaderProviderBuilder();
  }
Returns a builder for the default REST ChannelProvider for this service.
java-vertexai/google-cloud-vertexai/src/main/java/com/google/cloud/vertexai/api/stub/EndpointServiceStubSettings.java