message: it is okay for blockchain IDs to be null
diff: @@ -18,7 +18,6 @@ export function makeCoreSessionRequest(appDomain, appMethods,
  thisDevice = '.default'
  }
  - // TODO: multi-device
  const appPublicKey = SECP256K1Client.derivePublicKey(appPrivateKey)
  const appPublicKeys = [{
  public_key: appPublicKey,
  @@ -113,7 +112,7 @@ export function getCoreSession(coreHost, corePort, apiPassword, appPrivateKey,
  }
  if (!blockchainId) {
  - return Promise.reject('No blockchain ID given')
  + blockchainId = null;
  }
  let payload = null
  