readAuthMessage = (decoder, y, permissionDeniedHandler) => {
  switch (decoding.readVarUint(decoder)) {
    case messagePermissionDenied:
      permissionDeniedHandler(y, decoding.readVarString(decoder));
  }
}
@param {decoding.Decoder} decoder
@param {Y.Doc} y
@param {PermissionDeniedHandler} permissionDeniedHandler