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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def put(self, id):
 """ Update a resource by bson ObjectId :returns: json string representation :rtype: JSON """

        try:
            #Async update flow
            object_ = json_util.loads(self.request.body)

            toa = self.request.headers.get("Caesium-TOA", None)

            obj_check = yield self.client.find_one_by_id(id)
            if not obj_check:
                self.raise_error(404, "Resource not found: %s" % id)
                self.finish()
                return

            if toa:

                stack = AsyncSchedulableDocumentRevisionStack(self.client.collection_name, self.settings, master_id=id)
                revision_id = yield stack.push(object_, int(toa), meta=self._get_meta_data())

                if isinstance(revision_id, str):
                    self.set_header("Caesium-TOA", toa)

                    #We add the id of the original request, because we don't want to infer this
                    #On the client side, as the state of the client code could change easily
                    #We want this request to return with the originating ID as well.
                    object_["id"] = id
                    self.return_resource(object_)
                else:
                    self.raise_error(404, "Revision not scheduled for object: %s" % id)

            else:
                if object_.get("_id"):
                    del object_["_id"]

                response = yield self.client.update(id, object_)

                if response.get("updatedExisting"):
                    object_ = yield self.client.find_one_by_id(id)
                    self.return_resource(object_)
                else:
                    self.raise_error(404, "Resource not found: %s" % id)

        except ValidationError as vex:
            self.logger.error("%s validation error" % self.object_name, vex)
            self.raise_error(400, "Your %s cannot be updated because it is missing required fields, see docs" % self.object_name)
        except ValueError as ex:
            self.raise_error(400, "Invalid JSON Body, check formatting. %s" % ex[0])
        except InvalidId as ex:
            self.raise_error(message="Your ID is malformed: %s" % id)
        except Exception as ex:
            self.logger.error(ex)
            self.raise_error()