code: public BoxRequestsMetadata.UpdateFileMetadata getUpdateFileMetadataRequest(String id, String scope, String template) {
          BoxRequestsMetadata.UpdateFileMetadata request = new BoxRequestsMetadata.UpdateFileMetadata(getFileMetadataUrl(id, scope, template), mSession);
          return request;
      }
docs: Gets a request that updates the metadata for a specific template on a file
  
  @param id    id of the file to retrieve metadata for
  @param scope    currently only global and enterprise scopes are supported
  @param template    metadata template to use
  @return  request to update metadata on a file