public RegistryClient.Factory newBaseImageRegistryClientFactory() {
    return newBaseImageRegistryClientFactory(baseImageConfiguration.getImageRegistry());
  }
Creates a new {@link com.google.cloud.tools.jib.registry.RegistryClient.Factory} for the base
image with fields from the build configuration. The server URL is derived from the base {@link
ImageConfiguration}.

@return a new {@link com.google.cloud.tools.jib.registry.RegistryClient.Factory}
jib-core/src/main/java/com/google/cloud/tools/jib/configuration/BuildContext.java