From d1c38d3ed8c9b2d4dadc3d1ce22c1e82017e652b Mon Sep 17 00:00:00 2001
From: donerancl <donera@mit.edu>
Date: Thu, 4 Apr 2024 12:19:34 -0400
Subject: [PATCH] fix check for CuttingLabel in generate_kekule_structure
 (squashed)

---
 rmgpy/molecule/resonance.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/rmgpy/molecule/resonance.py b/rmgpy/molecule/resonance.py
index 89b0ab3d78..b207568e71 100644
--- a/rmgpy/molecule/resonance.py
+++ b/rmgpy/molecule/resonance.py
@@ -62,6 +62,7 @@
 from rmgpy.molecule.graph import Vertex
 from rmgpy.molecule.kekulize import kekulize
 from rmgpy.molecule.molecule import Atom, Bond, Molecule
+from rmgpy.molecule.fragment import CuttingLabel
 
 
 def populate_resonance_algorithms(features=None):
@@ -827,7 +828,7 @@ def generate_kekule_structure(mol):
     cython.declare(atom=Vertex, molecule=Graph)
 
     for atom in mol.atoms:
-        if not isinstance(atom, Atom):
+        if isinstance(atom,CuttingLabel):
             continue
         if atom.atomtype.label == 'Cb' or atom.atomtype.label == 'Cbf':
             break