public @Nullable X509Certificate getCertificate(@NotNull String alias) {
      myReadLock.lock();
      try {
        return (X509Certificate)myKeyStore.getCertificate(alias);
      }
      catch (KeyStoreException e) {
        return null;
      }
      finally {
        myReadLock.unlock();
      }
    }
public @Nullable X509Certificate getCertificate(@NotNull String alias)