code: def CacheObject(self, identifier, vfs_object):
      
      if identifier in self._values:
        raise KeyError('Object already cached for identifier: {0:s}'.format(
            identifier))
  
      if len(self._values) == self._maximum_number_of_cached_values:
        raise errors.CacheFullError('Maximum number of cached values reached.')
  
      self._values[identifier] = ObjectsCacheValue(vfs_object)
docs: Caches a VFS object.
  
      This method ignores the cache value reference count.
  
      Args:
        identifier (str): VFS object identifier.
        vfs_object (object): VFS object to cache.
  
      Raises:
        CacheFullError: if he maximum number of cached values is reached.
        KeyError: if the VFS object already is cached.