class_docstr: Base class for expressions (ShaderObjects that do not have a
  definition nor dependencies)
class_docstr_tok: ["Base","class","for","expressions","(","ShaderObjects","that","do","not","have","a","definition","nor","dependencies",")"]
code: def definition(self, names, version):
      # expressions are declared inline.
      return None
  
file_path: vispy/vispy/visuals/shaders/expression.py
imports: from .shader_object import ShaderObject
label_desc: Use image node_id 1 for calling the Expression obj's underlying member method code with example usage: obj.definition(names, version) and returns: None