Merge branch 'release/4.20.1' into master

docs/main/changelog.rst

@@ -7,6 +7,10 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+4.20.1
+------
+- Refactor containers module.
+
 4.20.0
 ------
 - Add container "self" injections.

src/dependency_injector/__init__.py

@@ -1,6 +1,6 @@
 """Top-level package."""
 
-__version__ = '4.20.0'
+__version__ = '4.20.1'
 """Version number.
 
 :type: str

src/dependency_injector/containers.pyx

@@ -560,15 +560,6 @@ class DeclarativeContainer(Container):
         for provider in six.itervalues(cls.providers):
             provider.reset_override()
 
-    @classmethod
-    def resolve_provider_name(cls, provider_to_resolve):
-        """Try to resolve provider name by its instance."""
-        for provider_name, container_provider in cls.providers.items():
-            if container_provider is provider_to_resolve:
-                return provider_name
-        else:
-            return None
-
 
 def override(object container):
     """:py:class:`DeclarativeContainer` overriding decorator.