code: def check_valency(mol):
      """
      Checks 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
  
imports: from rdkit import Chem
  import numpy
  import networkx
  import collections
  from collections import defaultdict
  import itertools
  import copy
  from scipy.spatial import distance_matrix
label_desc: Use image node_id 14 for calling a global function with example usage: check_valency(mol) and returns: True, False