This code accompanies the Free your mind (map) with Groovy article in the February 2013 edition of GroovyMag.
You will require Freemind version 0.9 to be able to follow the examples.
The first example in the article relates to Foo.mm and walk_and_count.groovy.
The second example relates to Bar.mm and walk_and_sum_leaf_atts.groovy.