code: def _is_small_molecule(pe):
      
      val = isinstance(pe, _bp('SmallMolecule')) or \
              isinstance(pe, _bpimpl('SmallMolecule')) or \
              isinstance(pe, _bp('SmallMoleculeReference')) or \
              isinstance(pe, _bpimpl('SmallMoleculeReference'))
      return val
docs: Return True if the element is a small molecule