|  | using System; | 
|  | using System.Collections.Generic; | 
|  | using System.Linq; | 
|  | using System.Text; | 
|  |  | 
|  | namespace OfficeOpenXml.FormulaParsing.Utilities | 
|  | { | 
|  | public static class ExtensionMethods | 
|  | { | 
|  | public static void IsNotNullOrEmpty(this ArgumentInfo<string> val) | 
|  | { | 
|  | if (string.IsNullOrEmpty(val.Value)) | 
|  | { | 
|  | throw new ArgumentException(val.Name + " cannot be null or empty"); | 
|  | } | 
|  | } | 
|  |  | 
|  | public static void IsNotNull<T>(this ArgumentInfo<T> val) | 
|  | where T : class | 
|  | { | 
|  | if (val.Value == null) | 
|  | { | 
|  | throw new ArgumentNullException(val.Name); | 
|  | } | 
|  | } | 
|  |  | 
|  | public static bool IsNumeric(this object obj) | 
|  | { | 
|  | if (obj == null) return false; | 
|  | return (obj.GetType().IsPrimitive || obj is double || obj is decimal || obj is System.DateTime || obj is TimeSpan); | 
|  | } | 
|  | } | 
|  | } |