I'm testing the sample app for Mobile Express Checkout Library with Android.

I'm getting `java.lang.NoClassDefFoundError: com.paypal.android.pizza.ResultDelegate` 

The error is on this Pizza.java line: `PayPal.fetchDeviceReferenceTokenWithAppID(this, appID, server, new ResultDelegate());`

I'm confused, i didnt find any info about that error on google, and also on the faq on paypal and x.com, so i don't know how to solve it.

I simply opened the sample code project and executed it.

This is the link to the project and the library: <https://www.x.com/sites/default/files/PayPal_MECL_1.0_Android-Developer-Package_0.zip>