class_docstr: Representation of a "namespace" that can be shared between
  different contexts. App backends can associate themselves with this
  object via add_ref().
  
  This object can be used to establish whether two contexts/canvases
  share objects, and can be used as a placeholder to store shared
  information, such as glyph atlasses.
class_docstr_tok: ["Representation","of","a","``","namespace","''","that","can","be","shared","between","different","contexts",".","App","backends","can","associate","themselves","with","this","object","via","add_ref","(",")",".","This","object","can","be","used","to","establish","whether","two","contexts\/canvases","share","objects",",","and","can","be","used","as","a","placeholder","to","store","shared","information",",","such","as","glyph","atlasses","."]
docstr: A reference (stored internally via a weakref) to an object
  that the backend system can use to obtain the low-level
  information of the "reference context". In Vispy this will
  typically be the CanvasBackend object.
docstr_tok: ["A","reference","(","stored","internally","via","a","weakref",")","to","an","object","that","the","backend","system","can","use","to","obtain","the","low-level","information","of","the","``","reference","context","''",".","In","Vispy","this","will","typically","be","the","CanvasBackend","object","."]
code: def ref(self):
      """A reference (stored internally via a weakref) to an object
      that the backend system can use to obtain the low-level
      information of the "reference context". In Vispy this will
      typically be the CanvasBackend object.
      """
      # Clean
      self._refs = [r for r in self._refs if (r() is not None)]
      # Get ref
      ref = self._refs[0]() if self._refs else None
      if ref is not None:
          return ref
      else:
          raise RuntimeError("No reference for available for GLShared")
  
imports: from copy import deepcopy
  import weakref
  from .glir import GlirQueue, BaseGlirParser, GlirParser, glir_logger
  from .wrappers import BaseGlooFunctions
  from ..None import config
label_desc: Use image node_id 7 for calling the GLShared obj's underlying member method code with example usage: obj.ref() and returns: ref