code: def get_brain_by_uid(uid, default=None):
      
      if not is_uid(uid):
          return default
  
      # we try to find the object with the UID catalog
      uc = get_tool("uid_catalog")
  
      # try to find the object with the reference catalog first
      brains = uc(UID=uid)
      if len(brains) != 1:
          return default
      return brains[0]
docs: Query a brain by a given UID
  
      :param uid: The UID of the object to find
      :type uid: string
      :returns: ZCatalog brain or None