public static PropertyRuleBuilder <T, TContext> PropagateNullValues <T, TContext>(this PropertyRuleBuilder <T, TContext> ruleBuilder)
     where T : class
     where TContext : class
 {
     ruleBuilder.SetPropagateNullValues(true);
     return(ruleBuilder);
 }
 public static void To <T, TContext>(this PropertyRuleBuilder <T, TContext> ruleBuilder, Expression <Func <TContext, T?> > targetExpression)
     where T : struct
     where TContext : class
 {
     ruleBuilder.SetTarget(targetExpression);
 }