public static void ThrowIfNullOrEmpty <T>(this ICollection <T> collection, string varName)
 {
     Proxy.ThrowIfNullOrEmpty(collection, varName);
 }
 public static void ThrowIfNullOrEmpty <T>(this ICollection <T> collection)
 {
     Proxy.ThrowIfNullOrEmpty(collection);
 }
 public static void ThrowIfNullOrEmpty(this string strValue, string varName)
 {
     Proxy.ThrowIfNullOrEmpty(strValue, varName);
 }
 public static void ThrowIfNull(this object obj, string varName)
 {
     Proxy.ThrowIfNull(obj, varName);
 }
 public static void ThrowIfNull(this object obj)
 {
     Proxy.ThrowIfNull(obj);
 }
 public static void ThrowOnFirstNull(params object[] objs)
 {
     Proxy.ThrowOnFirstNull(objs);
 }