create base class methods for _create_arithmetic_method, _create_comparison_method

Author: jbrockmendel

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)