function testGenerateKeyProducesTwoKeyPairs() {
  var fn = goog.bind(keyGenerator.generateKey, keyGenerator,
      'test <test@example.com>', e2e.signer.Algorithm['ECDSA'], 256,
      e2e.cipher.Algorithm['ECDH'], 256);

  assertUndefined(keyGenerator.eccCount_);
  fn();
  assertEquals(keyGenerator.eccCount_, 2);
  fn();
  assertEquals(keyGenerator.eccCount_, 4);
}
Ensure that generateKey always produces 2 key pairs
This is an assumption that we currently make when backing up / restoring
using backup key codes