diff --git a/pandas/core/arrays/base.py b/pandas/core/arrays/base.py
index fe4e461b0bd4f..d7bc163584969 100644
--- a/pandas/core/arrays/base.py
+++ b/pandas/core/arrays/base.py
@@ -634,6 +634,11 @@ class ExtensionOpsMixin(object):
     """
     A base class for linking the operators to their dunder names
     """
+
+    @classmethod
+    def _create_arithmetic_method(cls, op):
+        raise AbstractMethodError(cls)
+
     @classmethod
     def _add_arithmetic_ops(cls):
         cls.__add__ = cls._create_arithmetic_method(operator.add)
@@ -657,6 +662,10 @@ def _add_arithmetic_ops(cls):
         cls.__divmod__ = cls._create_arithmetic_method(divmod)
         cls.__rdivmod__ = cls._create_arithmetic_method(ops.rdivmod)
 
+    @classmethod
+    def _create_comparison_method(cls, op):
+        raise AbstractMethodError(cls)
+
     @classmethod
     def _add_comparison_ops(cls):
         cls.__eq__ = cls._create_comparison_method(operator.eq)
diff --git a/pandas/tests/series/test_arithmetic.py b/pandas/tests/series/test_arithmetic.py
index f4bdb7ba86aaf..9f948e77f3d49 100644
--- a/pandas/tests/series/test_arithmetic.py
+++ b/pandas/tests/series/test_arithmetic.py
@@ -561,7 +561,6 @@ def test_td64series_add_int_series_invalid(self, tdser):
         with pytest.raises(TypeError):
             tdser + Series([2, 3, 4])
 
-    @pytest.mark.xfail(reason='GH#19123 integer interpreted as nanoseconds')
     def test_td64series_radd_int_series_invalid(self, tdser):
         with pytest.raises(TypeError):
             Series([2, 3, 4]) + tdser
@@ -570,7 +569,6 @@ def test_td64series_sub_int_series_invalid(self, tdser):
         with pytest.raises(TypeError):
             tdser - Series([2, 3, 4])
 
-    @pytest.mark.xfail(reason='GH#19123 integer interpreted as nanoseconds')
     def test_td64series_rsub_int_series_invalid(self, tdser):
         with pytest.raises(TypeError):
             Series([2, 3, 4]) - tdser
@@ -611,9 +609,7 @@ def test_td64series_add_sub_numeric_scalar_invalid(self, scalar, tdser):
     @pytest.mark.parametrize('vector', [
         np.array([1, 2, 3]),
         pd.Index([1, 2, 3]),
-        pytest.param(Series([1, 2, 3]),
-                     marks=pytest.mark.xfail(reason='GH#19123 integer '
-                                                    'interpreted as nanos'))
+        Series([1, 2, 3])
     ])
     def test_td64series_add_sub_numeric_array_invalid(self, vector,
                                                       dtype, tdser):
@@ -777,10 +773,7 @@ def test_td64series_mul_numeric_array(self, vector, dtype, tdser):
                                        'float64', 'float32', 'float16'])
     @pytest.mark.parametrize('vector', [
         np.array([20, 30, 40]),
-        pytest.param(pd.Index([20, 30, 40]),
-                     marks=pytest.mark.xfail(reason='__mul__ raises '
-                                                    'instead of returning '
-                                                    'NotImplemented')),
+        pd.Index([20, 30, 40]),
         Series([20, 30, 40])
     ])
     def test_td64series_rmul_numeric_array(self, vector, dtype, tdser):
@@ -816,12 +809,8 @@ def test_td64series_mul_numeric_scalar(self, one, tdser):
 
     @pytest.mark.parametrize('two', [
         2, 2.0,
-        pytest.param(np.array(2),
-                     marks=pytest.mark.xfail(reason='GH#19011 is_list_like '
-                                                    'incorrectly True.')),
-        pytest.param(np.array(2.0),
-                     marks=pytest.mark.xfail(reason='GH#19011 is_list_like '
-                                                    'incorrectly True.')),
+        np.array(2),
+        np.array(2.0),
     ])
     def test_td64series_div_numeric_scalar(self, two, tdser):
         # GH#4521
diff --git a/pandas/util/_decorators.py b/pandas/util/_decorators.py
index 7d5753d03f4fc..6d712b1f85856 100644
--- a/pandas/util/_decorators.py
+++ b/pandas/util/_decorators.py
@@ -339,48 +339,3 @@ def make_signature(func):
     if spec.keywords:
         args.append('**' + spec.keywords)
     return args, spec.args
-
-
-class docstring_wrapper(object):
-    """
-    Decorator to wrap a function and provide
-    a dynamically evaluated doc-string.
-
-    Parameters
-    ----------
-    func : callable
-    creator : callable
-        return the doc-string
-    default : str, optional
-        return this doc-string on error
-    """
-    _attrs = ['__module__', '__name__',
-              '__qualname__', '__annotations__']
-
-    def __init__(self, func, creator, default=None):
-        self.func = func
-        self.creator = creator
-        self.default = default
-        update_wrapper(
-            self, func, [attr for attr in self._attrs
-                         if hasattr(func, attr)])
-
-    def __get__(self, instance, cls=None):
-
-        # we are called with a class
-        if instance is None:
-            return self
-
-        # we want to return the actual passed instance
-        return types.MethodType(self, instance)
-
-    def __call__(self, *args, **kwargs):
-        return self.func(*args, **kwargs)
-
-    @property
-    def __doc__(self):
-        try:
-            return self.creator()
-        except Exception as exc:
-            msg = self.default or str(exc)
-            return msg