docs: def get_notes(ref_key, ref_id, **kwargs):
      """
          Get all the notes for a resource, identifed by ref_key and ref_ido.
          Returns [] if no notes are found or if the resource doesn't exist.
      """
      notes = db.DBSession.query(Note).filter(Note.ref_key==ref_key)
      if ref_key == 'NETWORK':
          notes = notes.filter(Note.network_id == ref_id)
      elif ref_key == 'NODE':
          notes = notes.filter(Note.node_id == ref_id)
      elif ref_key == 'LINK':
          notes = notes.filter(Note.link_id == ref_id)
      elif ref_key == 'GROUP':
          notes = notes.filter(Note.group_id == ref_id)
      elif ref_key == 'PROJECT':
          notes = notes.filter(Note.project_id == ref_id)
      elif ref_key == 'SCENARIO':
          notes = notes.filter(Note.scenario_id == ref_id)
      else:
          raise HydraError("Ref Key %s not recognised.")
  
      note_rs = notes.all()
  
      return note_rs