public IEnumerable <ValidationResult> Validate(ValidationContext validationContext)
 {
     // Check if the string is a valid JSON object.
     if (Edges.IsNullOrInvalidJsonObject <IEnumerable <(string, string)> >())
     {
         yield return(new ValidationResult("The value is not a valid JSON string.", new List <string> {
             nameof(Edges)
         }));
     }
     // Check if the string is a valid JSON object.
     if (TargetNodes.IsNullOrInvalidJsonObject <IEnumerable <string> >())
     {
         yield return(new ValidationResult("The value is not a valid JSON string.", new List <string> {
             nameof(TargetNodes)
         }));
     }
     // Check if the string is a valid JSON object.
     if (PreferredNodes.IsNullOrInvalidJsonObject <IEnumerable <string> >())
     {
         yield return(new ValidationResult("The value is not a valid JSON string.", new List <string> {
             nameof(PreferredNodes)
         }));
     }
 }