Add additional shortcuts for top level package

dependency_injector/__init__.py

@@ -15,15 +15,27 @@ from .providers import Value
 from .providers import Callable
 from .providers import Config
 
+from .injections import Injection
 from .injections import KwArg
 from .injections import Attribute
 from .injections import Method
 from .injections import inject
 
+from .utils import is_provider
+from .utils import ensure_is_provider
+from .utils import is_injection
+from .utils import ensure_is_injection
+from .utils import is_kwarg_injection
+from .utils import is_attribute_injection
+from .utils import is_method_injection
+
 from .errors import Error
 
 
-__all__ = ('AbstractCatalog',
+__all__ = (
+    # Catalogs
+    'AbstractCatalog',
+    'override',
 
     # Providers
     'Provider',
@@ -42,10 +54,17 @@ __all__ = ('AbstractCatalog',
     'KwArg',
     'Attribute',
     'Method',
-
-           # Decorators
-           'override',
     'inject',
 
+    # Utils
+    'is_provider',
+    'ensure_is_provider',
+    'is_injection',
+    'ensure_is_injection',
+    'is_kwarg_injection',
+    'is_attribute_injection',
+    'is_method_injection',
+
     # Errors
-           'Error')
+    'Error',
+)