src/client/pfs.go
func (c APIClient) PutFileWriter(repoName string, commitID string, path string) (io.WriteCloser, error) {
	pfc, err := c.newOneoffPutFileClient()
	if err != nil {
		return nil, err
	}
	return pfc.PutFileWriter(repoName, commitID, path)
}
func (c APIClient) PutFileWriter(repoName string, commitID string, path string) (io.WriteCloser, error) {
	pfc, err := c.newOneoffPutFileClient()
	if err != nil {
		return nil, err
	}
	return pfc.PutFileWriter(repoName, commitID, path)
}
// PutFileWriter writes a file to PFS.
// NOTE: PutFileWriter returns an io.WriteCloser you must call Close on it when
// you are done writing.