class V8::JSError

def backtrace(*modifiers)
  trace_framework = modifiers.include?(:framework)
  trace_ruby = modifiers.length == 0 || modifiers.include?(:ruby)
  trace_javascript = modifiers.length == 0 || modifiers.include?(:javascript)
  mixed = []
  rbcontext = []
  jscontext = []
  @boundaries.each do |b|
    rbframes = b.rbframes.dup
    rbcontext.reverse_each do |frame|
      if frame == rbframes.last
        rbframes.pop
      else
        break
      end
    end if trace_ruby
    jsframes = b.jsframes.dup
    jscontext.reverse_each do |frame|
      if frame == jsframes.last
        jsframes.pop
      else
        break
      end
    end if trace_javascript
    rbcontext = b.rbframes
    jscontext = b.jsframes
    rbframes.reject! {|f| f =~ /lib\/v8\/.*\.rb/} unless trace_framework
    mixed.unshift(*rbframes) if trace_ruby
    mixed.unshift(*jsframes) if trace_javascript
  end
  return mixed
end