class_docstr: Filter used to color visuals by a picking ID.
  
  Note that the ID color uses the alpha channel, so this may not be used
  with blending enabled.
code: def id(self):
      return self._id
  
file_path: vispy/vispy/visuals/filters/picking.py
imports: import struct
  from .base_filter import Filter
label_desc: Use image node_id 2 for calling the PickingFilter obj's underlying member method code with example usage: obj.id() and returns: self