code: def tool_classpath(self, key, scope=None):
      
      return self.tool_classpath_from_products(self.context.products, key, scope=self._scope(scope))
docs: Get a classpath for the tool previously registered under key in the given scope.
  
      :API: public
  
      :param string key: The key the tool configuration was registered under.
      :param string scope: The scope the tool configuration was registered under; the task scope by
                           default.
      :returns: A list of paths.
      :rtype: list