Create an entry located at ``location``.
        
        Args:
            location: String or :class:`LocationDescriptor` to describe a "separator location" (i.e. dir1/dir2/dir3 for
                instance).
            element: Element to store.
            delete_elem: Delete old element or not if it exist?
        
        Returns:
            The created node with the element.
            
        Notes:
            The different sub locations entries **must** exist and the last may or may not already exist.
            Use the more strict :meth:`add_unique_element` method if needed.
            
            You don't need to have a common root node. We internally use a dummy root node.

def add_element(self, location, element, delete_elem=False):
        """
        Create an entry located at ``location``.
        
        Args:
            location: String or :class:`LocationDescriptor` to describe a "separator location" (i.e. dir1/dir2/dir3 for
                instance).
            element: Element to store.
            delete_elem: Delete old element or not if it exist?
        
        Returns:
            The created node with the element.
            
        Notes:
            The different sub locations entries **must** exist and the last may or may not already exist.
            Use the more strict :meth:`add_unique_element` method if needed.
            
            You don't need to have a common root node. We internally use a dummy root node.
        """
        return self._create_entry(location, element, unique=False, delete_element=delete_elem)