class_docstr: Loads a template from a Python dict mapping template names to
  template source.  This loader is useful for unittesting:
  
  >>> loader = DictLoader({'index.html': 'source here'})
  
  Because auto reloading is rarely useful this is disabled per default.
class_docstr_tok: ["Loads","a","template","from","a","Python","dict","mapping","template","names","to","template","source",".","This","loader","is","useful","for","unittesting",":",">",">",">","loader","=","DictLoader","(","{","'index.html","'",":","'source","here","'","}",")","Because","auto","reloading","is","rarely","useful","this","is","disabled","per","default","."]
code: def get_source(
      self, environment: "Environment", template: str
  ) -> t.Tuple[str, None, t.Callable[[], bool]]:
      if template in self.mapping:
          source = self.mapping[template]
          return (
              source,
              None,
              lambda: source == self.mapping.get(template),
          )
      raise TemplateNotFound(template)
  
imports: import importlib.util
  import os
  import posixpath
  import sys
  import pkgutil
  import typing
  import weakref
  import zipimport
  from collections import abc
  from hashlib import sha1
  from importlib import import_module
  from types import ModuleType
  from .exceptions import TemplateNotFound
  from .utils import internalcode
  from .utils import open_if_exists
  import __res
label_desc: Use image node_id 2 for calling the DictLoader obj's underlying member method code with example usage: obj.get_source(environment, template) and returns: source,  None,  function