func (h *dbHashTree) PutFileOverwrite(path string, objects []*pfs.Object, overwriteIndex *pfs.OverwriteIndex, sizeDelta int64) error {
	return h.putFile(path, objects, overwriteIndex, sizeDelta, false)
}
func (h *dbHashTree) PutFileOverwrite(path string, objects []*pfs.Object, overwriteIndex *pfs.OverwriteIndex, sizeDelta int64) error {
	return h.putFile(path, objects, overwriteIndex, sizeDelta, false)
}
// PutFileOverwrite is the same as PutFile, except that instead of
// appending the objects to the end of the given file, the objects
// are inserted to the given index, and the existing objects starting
// from the given index are removed.