def threads_list(io_handler, max_depth=1):
        """
        Lists the active threads and their current code line
        """
        # Normalize maximum depth
        try:
            max_depth = int(max_depth)
            if max_depth < 1:
                max_depth = None
        except (ValueError, TypeError):
            max_depth = None

        # pylint: disable=W0212
        try:
            # Extract frames
            frames = sys._current_frames()

            # Get the thread ID -> Thread mapping
            names = threading._active.copy()
        except AttributeError:
            io_handler.write_line("sys._current_frames() is not available.")
            return

        # Sort by thread ID
        thread_ids = sorted(frames.keys())
        lines = []
        for thread_id in thread_ids:
            # Get the corresponding stack
            stack = frames[thread_id]

            # Try to get the thread name
            try:
                name = names[thread_id].name
            except KeyError:
                name = "<unknown>"

            # Construct the code position
            lines.append("Thread ID: {0} - Name: {1}".format(thread_id, name))
            lines.append("Stack Trace:")

            trace_lines = []
            depth = 0
            frame = stack
            while frame is not None and (
                max_depth is None or depth < max_depth
            ):
                # Store the line information
                trace_lines.append(format_frame_info(frame))

                # Previous frame...
                frame = frame.f_back
                depth += 1

            # Reverse the lines
            trace_lines.reverse()

            # Add them to the printed lines
            lines.extend(trace_lines)
            lines.append("")

        lines.append("")

        # Sort the lines
        io_handler.write("\n".join(lines))
Lists the active threads and their current code line