code: def _(op: ops.Barrier, drawer, layer, _):
      mapped_wires = (
          op.wires
          if len(op.wires) != 0
          else list(range(drawer.n_wires))
      )
      ymin = min(mapped_wires) - 0.5
      ymax = max(mapped_wires) + 0.5
      drawer.ax.vlines(layer - 0.05, ymin=ymin, ymax=ymax)
      drawer.ax.vlines(layer + 0.05, ymin=ymin, ymax=ymax)
  
imports: from collections import namedtuple
  from functools import singledispatch
  import pennylane
  from pennylane import ops
  from pennylane.measurements import MidMeasureMP
  from .mpldrawer import MPLDrawer
  from .drawable_layers import drawable_layers
  from .utils import convert_wire_order, unwrap_controls, cwire_connections, default_bit_map
  from .style import _set_style
label_desc: Use image node_id 9 for calling a global function with example usage: _(op, drawer, layer, _) without return types