text: SELECT mol_to_smiles(mol_from_smiles('C1OCCCC1'));
  
  SELECT mol_to_smiles(mol_from_smiles('OC=CC'));
  SELECT mol_to_smiles(mol_from_smiles('OC=CC'), canonical => false);
  
  SELECT mol_to_smiles(mol_from_smiles('F[C@](Cl)(Br)I'));
  SELECT mol_to_smiles(mol_from_smiles('F[C@](Cl)(Br)I'), isomeric => false);
  SELECT mol_to_smiles(mol_from_smiles('F[C@](Cl)(Br)I'), all_bonds_explicit => true);
  
  SELECT mol_to_smarts(mol_from_smarts('c1ccc[n,c]c1'));
  
  SELECT mol_to_molblock(mol_from_smiles(''));
  SELECT mol_to_smiles(mol_from_molblock(
      (Chr(10) || Chr(10) || Chr(10) ||
      '  0  0  0  0  0  0  0  0  0  0999 V2000' || Chr(10) ||
      'M  END')::cstring
      ));
  