/// <summary>
/// Returns a unique key for the chemical structure.
/// </summary>
/// <returns>A canonical Smiles string representing the unique key for the chemical structure.</returns>
public string GetUniqueKey()
{
string uniqueKey = String.Empty;
using (Indigo indigo = new Indigo())
{
IndigoObject structure = CreateIndigoStructure(indigo);
uniqueKey = structure.canonicalSmiles();
structure.Dispose();
}
return(uniqueKey);
}