code: def check_valency(mol):
      """
      Check that no atoms in the mol have exceeded their possible
      valency.
  
      Args:
          mol: Rdkit mol object
  
      :rtype:
          :class:`bool`, True if no valency issues, False otherwise
      """
  
      try:
          s = Chem.MolToSmiles(mol, isomericSmiles=True)
          m = Chem.MolFromSmiles(s)
          Chem.SanitizeMol(
              m, sanitizeOps=Chem.SanitizeFlags.SANITIZE_PROPERTIES
          )
          return True
      except:
          return False
  
file_path: DIG/dig/ggraph/utils/environment.py
imports: import copy
  import itertools
  import networkx
  from rdkit import Chem, DataStructs
  from rdkit.Chem import AllChem, rdMolDescriptors
  from rdkit.Chem.Descriptors import MolLogP, qed
  from rdkit.Chem.FilterCatalog import FilterCatalogParams, FilterCatalog
  from .sascorer import calculateScore
label_desc: Use image node_id 3 for calling a global function with example usage: check_valency(mol) and returns: True, False