def evalRPN(self, tokens):
        return self.eval_postfix(tokens)
Testing GeoQuerySet.perimeter() on 3D fields.
dataset/ETHPy150Open algorhythms/LintCode/Evaluate Reverse Polish Notation.py/Solution.evalRPN--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/django/contrib/gis/tests/geo3d/tests.py/Geo3DTest.test04_perimeter