code: def install(cls, env):
      if not hasattr(env, "entity_all_entities"):
          entities = cls()
          env.entity_all_entities = entities
      return env.entity_all_entities
  
imports: from collections import defaultdict, abc
  from typing import cast
  from docutils import nodes
  from docutils.parsers.rst import Directive
  import sphinx
  from sphinx.locale import _
  from sphinx.util.docutils import SphinxDirective
  from sphinx.errors import ExtensionError
  from conf import languages
label_desc: Use image node_id 2 for calling the AllEntities obj's underlying member method code with example usage: obj.install(cls, env) and returns: env