Set the local context to ExtendedContext for two doctests which

require the ``InvalidOperation`` trap to be ``False``.

Author: mbyrnepr2

Lib/_pydecimal.py

@@ -1796,10 +1796,10 @@ def __round__(self, n=None):
         Decimal('123.46')
         >>> round(Decimal('123.456'), -2)
         Decimal('1E+2')
-        >>> setcontext(ExtendedContext)
-        >>> round(Decimal('-Infinity'), 37)
+        >>> with localcontext(ExtendedContext):
+        ...     round(Decimal('-Infinity'), 37)
+        ...     round(Decimal('sNaN123'), 0)
         Decimal('NaN')
-        >>> round(Decimal('sNaN123'), 0)
         Decimal('NaN123')
 
         """