message: Compatibility with TypeScript 3.9
diff: @@ -486,7 +486,7 @@ export async function generateKeyPair(
  const ephemeralKeyPair = await window.crypto.subtle.generateKey(
  params, /* extractable= */ true,
  algorithm == 'ECDH' ? ['deriveKey', 'deriveBits'] : ['sign', 'verify']);
  - return ephemeralKeyPair;
  + return ephemeralKeyPair as CryptoKeyPair;
  }
  export async function exportCryptoKey(cryptoKey: CryptoKey):
  