code: def get_all(self, cbobjects):
          
          try:
              with self._lock:
                  return [self._metadata[x] for x in cbobjects]
          except KeyError:
              # Note that if this error gets thrown then the assumption that OSX
              # will pass back to callbacks the exact CoreBluetooth objects that
              # were used previously is broken! (i.e. the CoreBluetooth objects
              # are not stateless)
              raise RuntimeError('Failed to find expected metadata for CoreBluetooth object!')
docs: Retrieve a list of metadata objects associated with the specified
          list of CoreBluetooth objects.  If an object cannot be found then an
          exception is thrown.