How to use the jsonpatch.PatchOperation function in jsonpatch

def test_patch_neq_other_objs(self):
        p = [{'op': 'test', 'path': '/test'}]
        patch = jsonpatch.JsonPatch(p)
        # a patch will always compare not-equal to objects of other types
        self.assertFalse(patch == p)
        self.assertFalse(patch == None)

        # also a patch operation will always compare
        # not-equal to objects of other types
        op = jsonpatch.PatchOperation(p[0])
        self.assertFalse(op == p[0])
        self.assertFalse(op == None)

if self.key >= key:
                self.key += 1
            else:
                key -= 1
        return key

    def _on_undo_add(self, path, key):
        if self.path == path:
            if self.key > key:
                self.key -= 1
            else:
                key -= 1
        return key


class AddOperation(PatchOperation):
    """Adds an object property or an array element."""

    def apply(self, obj):
        try:
            value = self.operation["value"]
        except KeyError as ex:
            raise InvalidJsonPatch(
                "The operation does not contain a 'value' member")

        subobj, part = self.pointer.to_last(obj)

        if isinstance(subobj, MutableSequence):
            if part == '-':
                subobj.append(value)  # pylint: disable=E1103

            elif part > len(subobj) or part < 0:

def _on_undo_add(self, path, key):
        if self.from_path == path:
            if self.from_key > key:
                self.from_key -= 1
            else:
                key -= 1
        if self.path == path:
            if self.key > key:
                self.key -= 1
            else:
                key += 1
        return key


class TestOperation(PatchOperation):
    """Test value by specified location."""

    def apply(self, obj):
        try:
            subobj, part = self.pointer.to_last(obj)
            if part is None:
                val = subobj
            else:
                val = self.pointer.walk(subobj, part)
        except JsonPointerException as ex:
            raise JsonPatchTestFailed(str(ex))

        try:
            value = self.operation['value']
        except KeyError as ex:
            raise InvalidJsonPatch(

def __eq__(self, other):
        if not isinstance(other, PatchOperation):
            return False
        return self.operation == other.operation

try:
            value = self.operation['value']
        except KeyError as ex:
            raise InvalidJsonPatch(
                "The operation does not contain a 'value' member")

        if val != value:
            msg = '{0} ({1}) is not equal to tested value {2} ({3})'
            raise JsonPatchTestFailed(msg.format(val, type(val),
                                                 value, type(value)))

        return obj


class CopyOperation(PatchOperation):
    """ Copies an object property or an array element to a new location """

    def apply(self, obj):
        try:
            from_ptr = JsonPointer(self.operation['from'])
        except KeyError as ex:
            raise InvalidJsonPatch(
                "The operation does not contain a 'from' member")

        subobj, part = from_ptr.to_last(obj)
        try:
            value = copy.deepcopy(subobj[part])
        except (KeyError, IndexError) as ex:
            raise JsonPatchConflict(str(ex))

        obj = AddOperation({

    @property
    def key(self):
        try:
            return int(self.pointer.parts[-1])
        except ValueError:
            return self.pointer.parts[-1]

    @key.setter
    def key(self, value):
        self.pointer.parts[-1] = str(value)
        self.location = self.pointer.path
        self.operation['path'] = self.location


class RemoveOperation(PatchOperation):
    """Removes an object property or an array element."""

    def apply(self, obj):
        subobj, part = self.pointer.to_last(obj)
        try:
            del subobj[part]
        except (KeyError, IndexError) as ex:
            msg = "can't remove non-existent object '{0}'".format(part)
            raise JsonPatchConflict(msg)

        return obj

    def _on_undo_remove(self, path, key):
        if self.path == path:
            if self.key >= key:
                self.key += 1

msg = "can't replace non-existent object '{0}'".format(part)
                raise JsonPatchConflict(msg)
        else:
            raise TypeError("invalid document type {0}".format(type(subobj)))

        subobj[part] = value
        return obj

    def _on_undo_remove(self, path, key):
        return key

    def _on_undo_add(self, path, key):
        return key


class MoveOperation(PatchOperation):
    """Moves an object property or an array element to new location."""

    def apply(self, obj):
        try:
            from_ptr = JsonPointer(self.operation['from'])
        except KeyError as ex:
            raise InvalidJsonPatch(
                "The operation does not contain a 'from' member")

        subobj, part = from_ptr.to_last(obj)
        try:
            value = subobj[part]
        except (KeyError, IndexError) as ex:
            raise JsonPatchConflict(str(ex))

        # If source and target are equal, this is a no-op

if self.key > key:
                self.key += 1
            else:
                key += 1
        return key

    def _on_undo_add(self, path, key):
        if self.path == path:
            if self.key > key:
                self.key -= 1
            else:
                key += 1
        return key


class ReplaceOperation(PatchOperation):
    """Replaces an object property or an array element by new value."""

    def apply(self, obj):
        try:
            value = self.operation["value"]
        except KeyError as ex:
            raise InvalidJsonPatch(
                "The operation does not contain a 'value' member")

        subobj, part = self.pointer.to_last(obj)

        if part is None:
            return value

        if isinstance(subobj, MutableSequence):
            if part > len(subobj) or part < 0: