/// <summary>
 /// Returns alias for declaration key.
 /// </summary>
 public static string GetAlias(IDeclKey declKey)
 {
     if (declKey.Module.ModuleName.StartsWith("DataCentric"))
     {
         return("dc");
     }
     // NodaTime classes should be implemented in python datacentric package.
     if (declKey.Module.ModuleName.StartsWith("NodaTime"))
     {
         return("dc");
     }
     throw new Exception($"Unknown module: {declKey.Module.ModuleName}");
 }
 /// <summary>
 /// Find single declaration by its module and name.
 /// </summary>
 public static IDecl FindByKey(this List <IDecl> declarations, IDeclKey key)
 {
     return(declarations.Single(d => d.Module.ModuleName == key.Module.ModuleName && d.Name == key.Name));
 }
 /// <summary>
 /// Check if provided entities belong to the same package.
 /// </summary>
 public static bool IsPackageEquals(IDecl decl, IDeclKey declKey)
 {
     return(GetPackage(decl) == GetPackage(declKey));
 }