docs: def remove_reserved_keys(self, op):
          """
          Remove reserved keywords from an op dict,
          which can then safely be passed into the db.
          
          Returns a new op dict, and the reserved fields
          """
          sanitized = {}
          reserved = {}
          
          for k in op.keys():
              if str(k) not in RESERVED_KEYS:
                  sanitized[str(k)] = copy.deepcopy(op[k])
              else:
                  reserved[str(k)] = copy.deepcopy(op[k])
                  
          return sanitized, reserved