>>> (indent 4)
    TreeNode lookupEntity(Iterable<TreeNode> iterable, int entity) => iterable
        .firstWhere((node) => (node.entity == entity), orElse: () => null);
<<<
    TreeNode lookupEntity(Iterable<TreeNode> iterable, int entity) => iterable
        .firstWhere((node) => (node.entity == entity), orElse: () => null);