code: def set_dashes(self, offset, dashes):
      self._dashes = offset, dashes
      if dashes == None:
          self.ctx.set_dash([], 0)  # switch dashes off
      else:
          self.ctx.set_dash(
              list(self.renderer.points_to_pixels(np.asarray(dashes))),
              offset,
          )
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  import gzip
  import sys
  import warnings
  import numpy
  from matplotlib.backend_bases import _Backend, FigureCanvasBase, FigureManagerBase, GraphicsContextBase, RendererBase
  from matplotlib.mathtext import MathTextParser
  from matplotlib.path import Path
  from matplotlib.transforms import Affine2D
  from matplotlib.font_manager import ttfFontProperty
label_desc: Use image node_id 7 for calling the GraphicsContextCairo obj's underlying member method code with example usage: obj.set_dashes(offset, dashes) without return types