/// <summary>
/// This method returns the list of genbankID with its corresponding accession.verison.
/// Throws an exception of any error accessing the database occurs.
/// </summary>
public static XmlDocument listAccessionVersions()
{
XmlDocument doc = new XmlDocument();
doc.AppendChild(dictionaryToXML(GDDL.listAccessionVersions(), doc));
return(doc);
}