<gh_stars>0
class Node:
    def __init__(self, condition, body):

        self.condition = condition
        self.body = body

    def visit(self, context):
        rvalue = None
        while self.condition.visit(context):
            rvalue = self.body.visit(context)
        return rvalue

class Node:
    def __init__(self, condition, body):

        self.condition = condition
        self.body = body

    def visit(self, context):
        rvalue = None
        while self.condition.visit(context):
            rvalue = self.body.visit(context)
        return rvalue