code: def set_capstyle(self, cs):
      self.ctx.set_line_cap(_api.check_getitem(self._capd, capstyle=cs))
      self._capstyle = cs
  
imports: import functools
  import gzip
  import math
  import numpy
  from ..None import _api, cbook, font_manager
  from matplotlib.backend_bases import _Backend, FigureCanvasBase, FigureManagerBase, GraphicsContextBase, RendererBase
  from matplotlib.font_manager import ttfFontProperty
  from matplotlib.path import Path
  from matplotlib.transforms import Affine2D
label_desc: Use image node_id 6 for calling the GraphicsContextCairo obj's underlying member method code with example usage: obj.set_capstyle(cs) without return types