code: def setchival(self, bondorder, rotation):
          
          rotation = [None, "@", "@@"][(rotation % 2)]
          # check to see if the bonds are attached
          if not bondorder: # use the default xatoms
              if len(self.oatoms) < 3 and self.explicit_hcount != 1:
                  raise PinkyError("Need to have an explicit hydrogen when specifying "\
                                    "chirality with less than three bonds")
                  
  
              self._chirality = chirality.T(self.oatoms,
                                              rotation)
              return
          if len(bondorder) != len(self.bonds):
              raise AtomError("The order of all bonds must be specified")
          
          for bond in bondorder:
              if bond not in self.bonds:
                  raise AtomError("Specified bonds to assign chirality are not attatched to atom")
  
          order = [bond.xatom(self) for bond in bonds]
          self._chirality = chirality.T(order, rotation)
docs: compute chiral ordering of surrounding atoms