function getBufferLoader(bufferViewLoader) {
  const resourceCache = bufferViewLoader._resourceCache;
  const buffer = bufferViewLoader._buffer;
  if (defined(buffer.uri)) {
    const baseResource = bufferViewLoader._baseResource;
    const resource = baseResource.getDerivedResource({
      url: buffer.uri,
    });
    return resourceCache.getExternalBufferLoader({
      resource: resource,
    });
  }
  return resourceCache.getEmbeddedBufferLoader({
    parentResource: bufferViewLoader._gltfResource,
    bufferId: bufferViewLoader._bufferId,
  });
}
Loads the resource.
@returns {Promise<GltfBufferViewLoader>} A promise which resolves to the loader when the resource loading is completed.
@private