Loop over all the notes within a specified namespace and issue a callback for each one.
If callback returns a non-zero value, this will stop looping.
| this |
a Repository. |
| notes_ref |
canonical name of the reference to use, or null to use the default ref. |
| callback |
a NoteCallback. |
| user_data |
callback user data. |
|
true if there was no error, false otherwise. |