def _split_scope(self, nodeid):
        """Assign a chunk id to a test node."""
        # If we have a chunk assignment for this node, return it.
        scope = self.test_chunks.get(nodeid)
        if scope is not None:
            return scope

        # If this is a node that should be clumped, clump it.
        for i, clump_word in enumerate(self.clumps):
            if clump_word in nodeid:
                return f"clump{i}"

        # Otherwise every node is a separate chunk.
        return nodeid
Assign a chunk id to a test node.
tests/balance_xdist_plugin.py