class DEBUGGER__::LineBreakpoint

def try_activate root_iseq = nil
  nearest = nil # NearestISeq
  iterate_iseq root_iseq do |iseq|
    iseq.traceable_lines_norec(line_events = {})
    lines = line_events.keys.sort
    if !lines.empty? && lines.last >= line
      nline = lines.bsearch{|l| line <= l}
      events = line_events[nline]
      next if events == [:RUBY_EVENT_B_CALL]
      if @hook_call &&
        events.include?(:RUBY_EVENT_CALL) &&
        self.line == iseq.first_lineno
        nline = iseq.first_lineno
      end
      if !nearest || ((line - nline).abs < (line - nearest.line).abs)
        nearest = NearestISeq.new(iseq, nline, events)
      elsif @hook_call &&
            nearest.line == iseq.first_line &&
            events.include?(:RUBY_EVENT_CALL)
        nearest = NearestISeq.new(iseq, nline, events)
      end
    end
  end
  if nearest
    activate_exact nearest.iseq, nearest.events, nearest.line
  end
end