move @annotate to py3compat

IPython/html/widgets/__init__.py

@@ -9,4 +9,4 @@ from .widget_int import IntTextWidget, BoundedIntTextWidget, IntSliderWidget, In
 from .widget_selection import RadioButtonsWidget, ToggleButtonsWidget, DropdownWidget, SelectWidget
 from .widget_selectioncontainer import TabWidget, AccordionWidget
 from .widget_string import HTMLWidget, LatexWidget, TextWidget, TextareaWidget
-from .interaction import interact, interactive, annotate, const
+from .interaction import interact, interactive, const

IPython/html/widgets/interaction.py

@@ -246,17 +246,3 @@ class const(HasTraits):
     description = Unicode('', help="Any Python object")
     def __init__(self, value, **kwargs):
         super(const, self).__init__(value=value, **kwargs)
-
-def annotate(**kwargs):
-    """Python 3 compatible function annotation for Python 2."""
-    if not kwargs:
-        raise ValueError('annotations must be provided as keyword arguments')
-    def dec(f):
-        if hasattr(f, '__annotations__'):
-            for k, v in kwargs.items():
-                f.__annotations__[k] = v
-        else:
-            f.__annotations__ = kwargs
-        return f
-    return dec
-