def f_add_leaf(self, *args, **kwargs):
return self._nn_interface._add_generic(self, type_name=LEAF,<EOL>group_type_name=GROUP,<EOL>args=args, kwargs=kwargs,<EOL>add_prefix=False)<EOL>
Adds an empty generic leaf under the current node.

        You can add to a generic leaves anywhere you want. So you are free to build
        your trajectory tree with any structure. You do not necessarily have to follow the
        four subtrees `config`, `parameters`, `derived_parameters`, `results`.

        If you are operating within these subtrees this simply calls the corresponding adding
        function.

        Be aware that if you are within a single run and you add items not below a group
        `run_XXXXXXXX` that you have to manually
        save the items. Otherwise they will be lost after the single run is completed.