class ActiveSupport::BacktraceCleaner

def minimum_first
  @minimum_first ||= self.class.minimum_first
end

def silence(backtrace)
  @silencers.each do |s|
    ix = 0
    backtrace = backtrace.reject do |line|
      ix += 1
      next if ix <= minimum_first
      s.call(line)
    end
  end
  backtrace = backtrace.to_a
  backtrace.insert(minimum_first, 'BacktraceCleaner.minimum_first ... and next silenced backtraces')
  backtrace
end