public RefUpdate.Result modifyFile(ChangeEdit edit,String file,RawInput content) throws AuthException, InvalidChangeOperationException, IOException {
  return modify(TreeOperation.CHANGE_ENTRY,edit,file,null,content);
}

public RefUpdate . Result modifyFile ( ChangeEdit edit , String file , RawInput content ) throws AuthException , InvalidChangeOperationException , IOException { return modify ( TreeOperation . CHANGE_ENTRY , edit , file , null , content ) ; }
modify file in existing change edit from its base commit .
