clean_backtrace

# File actionpack/lib/action_controller/assertions.rb, line 53
    def clean_backtrace(&block)
      yield
    rescue Test::Unit::AssertionFailedError => error
      framework_path = Regexp.new(File.expand_path("#{File.dirname(__FILE__)}/assertions"))
      error.backtrace.reject! { |line| File.expand_path(line) =~ framework_path }
      raise
    end