public ImageRequestBuilder setSource(Uri uri) {
    Preconditions.checkNotNull(uri);

    mSourceUri = uri;
    return this;
  }
Sets the source uri (both network and local uris are supported). Note: this will enable disk
caching for network sources, and disable it for local sources.

@param uri the uri to fetch the image from
@return the updated builder instance
imagepipeline/src/main/java/com/facebook/imagepipeline/request/ImageRequestBuilder.java