code: public boolean
          engineEntryInstanceOf(String alias,
                                Class<? extends KeyStore.Entry> entryClass)
      {
          if (entryClass == KeyStore.TrustedCertificateEntry.class) {
              return engineIsCertificateEntry(alias);
          }
          if (entryClass == KeyStore.PrivateKeyEntry.class) {
              return engineIsKeyEntry(alias) &&
                          engineGetCertificate(alias) != null;
          }
          if (entryClass == KeyStore.SecretKeyEntry.class) {
              return engineIsKeyEntry(alias) &&
                          engineGetCertificate(alias) == null;
          }
          return false;
      }
docs: Determines if the keystore {@code Entry} for the specified
  {@code alias} is an instance or subclass of the specified
  {@code entryClass}.
  
  @param alias the alias name
  @param entryClass the entry class
  
  @return true if the keystore {@code Entry} for the specified
  {@code alias} is an instance or subclass of the
  specified {@code entryClass}, false otherwise
  
  @since 1.5