code: public static EphemeralKey create(Map<String, Object> params, RequestOptions options)
        throws StripeException {
      if (options.getStripeVersionOverride() == null) {
        throw new IllegalArgumentException("`stripeVersionOverride` must be specified in "
            + "RequestOptions with stripe version of your mobile client.");
      }
  
      return request(RequestMethod.POST, classUrl(EphemeralKey.class), params, EphemeralKey.class,
          options);
    }
docs: Creates an ephemeral API key for a given resource.
  
  @param params request parameters
  @param options request options. {@code stripeVersion} is required when creating ephemeral
  keys. it must have non-null {@link RequestOptions#getStripeVersionOverride()}.
  @return the new ephemeral key