class_docstr: OSMesa backend for Canvas
class_docstr_tok: ["OSMesa","backend","for","Canvas"]
code: def _vispy_set_current(self):
      if self._native_context is None:
          raise RuntimeError("Native context is None")
      if self._pixels is None:
          raise RuntimeError("Pixel buffer has already been deleted")
  
      ok = self._native_context.make_current(
          self._pixels, self._size[0], self._size[1]
      )
      if not ok:
          raise RuntimeError("Failed attaching OSMesa rendering buffer")
  
imports: from __future__ import division
  from ...util.ptime import time
  from ..base import BaseApplicationBackend, BaseCanvasBackend, BaseTimerBackend
  from ...gloo import gl
  from time import sleep
label_desc: Use image node_id 2 for calling the CanvasBackend obj's underlying member method code with example usage: obj._vispy_set_current() without return types