(self)
Execute the optree. When calling `execute()`, there must be one and only
        one `assign` operation at the very top of the op-tree. The corresponding
        backend's execute function will be called.
Execute the optree. When calling `execute()`, there must be one and only
        one `assign` operation at the very top of the op-tree. The corresponding
        backend's execute function will be called.
Execute the optree . When calling execute () there must be one and only one assign operation at the very top of the op - tree . The corresponding backend s execute function will be called .
def execute(self):
        """
        Execute the optree. When calling `execute()`, there must be one and only
        one `assign` operation at the very top of the op-tree. The corresponding
        backend's execute function will be called.
        """

        assert(self[0]["op"] == "assign")

        backend = self[1].backend

        if isinstance(backend, Backend):
            return backend.execute(self)
        else:
            raise NotImplementedError()
def execute ( self ) : assert ( self [ 0 ] [ "op" ] == "assign" ) backend = self [ 1 ] . backend if isinstance ( backend , Backend ) : return backend . execute ( self ) else : raise NotImplementedError ( )