Problem with Google task demo API

I've been following the launch of the Google Tasks API, and I was just to start playing with it, but I'm not be able to compile the first steps, I'm having an

Exception in thread "main" java.lang.NoClassDefFoundError: com/google/common/base/Preconditions

Has somebody have a similar error or knows how can I fix this? I'm following the example in http://code.google开发者_C百科.com/intl/es-ES/apis/tasks/v1/using.html#retrieving_task_lists

Thanks in advance

The Java google API client library appears to have a dependency on Google's Guava library. You'll need to add guava-r09.jar (contained in the linked zip file) and the jars for some or all of the other dependencies to your classpath. Or you could use Maven, in which case the dependencies would be taken care of for you.