code: def set_dashes(self, dash_offset, dash_list):
      GraphicsContextBase.set_dashes(self, dash_offset, dash_list)
  
      if dash_list == None:
          self.gdkGC.line_style = gdk.LINE_SOLID
      else:
          pixels = self.renderer.points_to_pixels(np.asarray(dash_list))
          dl = [max(1, int(np.round(val))) for val in pixels]
          self.gdkGC.set_dashes(dash_offset, dl)
          self.gdkGC.line_style = gdk.LINE_ON_OFF_DASH
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  import warnings
  import gobject
  import gtk
  import pango
  import numpy
  import matplotlib
  from matplotlib import rcParams
  from matplotlib._pylab_helpers import Gcf
  from matplotlib.backend_bases import _Backend, FigureCanvasBase, FigureManagerBase, GraphicsContextBase, RendererBase
  from matplotlib.cbook import warn_deprecated
  from matplotlib.mathtext import MathTextParser
  from matplotlib.transforms import Affine2D
  from matplotlib.backends._backend_gdk import pixbuf_get_pixels_array
label_desc: Use image node_id 5 for calling the GraphicsContextGDK obj's underlying member method code with example usage: obj.set_dashes(dash_offset, dash_list) without return types