class_docstr: Basic in-memory dict-based object for saving Task Records.
  
  This is the first object to present the DB interface
  for logging tasks out of memory.
  
  The interface is based on MongoDB, so adding a MongoDB
  backend should be straightforward.
docstr: Update the data in an existing record.
docstr_tok: ["Update","the","data","in","an","existing","record","."]
code: def update_record(self, msg_id, rec):
      """Update the data in an existing record."""
      if msg_id in self._culled_ids:
          raise KeyError("Record %r has been culled for size" % msg_id)
      self._check_dates(rec)
      _rec = self._records[msg_id]
      self._drop_bytes(_rec)
      _rec.update(rec)
      self._add_bytes(_rec)
  
imports: import copy
  from copy import deepcopy
  from datetime import datetime
  from traitlets import Dict, Float, Integer, Unicode
  from traitlets.config.configurable import LoggingConfigurable
  from ..util import ensure_timezone
label_desc: Use image node_id 11 for calling the DictDB obj's underlying member method code with example usage: obj.update_record(msg_id, rec) without return types