def append(self, annotation):
        """Add an annotation.

        Args:
            annotation (gkeepapi.node.Annotation): An Annotation object.

        Returns:
            gkeepapi.node.Annotation: The Annotation.
        """
        self._annotations[annotation.id] = annotation
        self._dirty = True
        return annotation
Add an annotation.

        Args:
            annotation (gkeepapi.node.Annotation): An Annotation object.

        Returns:
            gkeepapi.node.Annotation: The Annotation.