Document both importlib.machinery.BuiltinImporter and FrozenImporter.

Doc/library/importlib.rst

@@ -61,7 +61,7 @@ providing custom importers can be found in :pep:`302`.
 Functions
 ---------
 
-.. function:: __import__(name, globals={}, locals={}, fromlist=\[\], level=0)
+.. function:: __import__(name, globals={}, locals={}, fromlist=list(), level=0)
 
     An implementation of the built-in :func:`__import__` function. See the
     built-in function's documentation for usage instructions.
@@ -76,3 +76,49 @@ Functions
     package name (e.g. ``import_module('..mod', 'pkg.subpkg')`` will import
     ``pkg.mod``). The specified module will be inserted into
     :data:`sys.modules` and returned.
+
+
+:mod:`importlib.machinery` -- Importers and path hooks
+------------------------------------------------------
+
+.. module:: importlib.machinery
+    :synopsis: Importers and path hooks
+
+This module contains the various objects that help :keyword:`import`
+find and load modules.
+
+.. class:: BuiltinImporter
+
+    :term:`Importer` for built-in modules. All known built-in modules are
+    listed in :data:`sys.builtin_module_names`.
+
+    Only class methods are defined by this class to alleviate the need for
+    instantiation.
+
+    .. method:: find_module(fullname, path=None)
+
+        Class method that allows this class to be a :term:`finder` for built-in
+        modules.
+
+    .. method:: load_module(fullname)
+
+        Class method that allows this class to be a :term:`loader` for built-in
+        modules.
+
+
+.. class:: FrozenImporter
+
+    :term:`Importer` for frozen modules.
+
+    Only class methods are defined by this class to alleviate the need for
+    instantiation.
+
+    .. method:: find_module(fullname, path=None)
+
+        Class method that allows this class to be a :term:`finder` for frozen
+        modules.
+
+    .. method:: load_module(fullname)
+
+        Class method that allows this class to be a :term:`loader` for frozen
+        modules.

Lib/importlib/NOTES

 to do
 /////
 
-* Document:
-
-    + The terms "importer", "finder", and "loader".
-    + machinery.BuiltinImporter.
-    + machinery.FrozenImporter.
-
 * Expose resolve_name().
 
 * Backport to Python 2.7.

Lib/importlib/_bootstrap.py

@@ -110,8 +110,8 @@ class BuiltinImporter:
             return None
         return cls if imp.is_builtin(fullname) else None
 
-    @staticmethod
-    def load_module(fullname):
+    @classmethod
+    def load_module(cls, fullname):
         """Load a built-in module."""
         if fullname not in sys.builtin_module_names:
             raise ImportError("{0} is not a built-in module".format(fullname))