Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data.Entity/System/Data/Metadata/Edm/util.cs

@@ -0,0 +1,51 @@
+//---------------------------------------------------------------------
+// <copyright file="Util.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+
+using System;
+using System.Collections.Generic;
+using System.Data.Common;
+using System.Diagnostics;
+using System.Text;
+
+namespace System.Data.Metadata.Edm
+{
+    /// <summary>
+    /// Class holding utility functions for metadata
+    /// </summary>
+    internal static class Util
+    {
+        #region Methods
+        /// <summary>
+        /// Throws an appropriate exception if the given item is a readonly, used when an attempt is made to change
+        /// a property
+        /// </summary>
+        /// <param name="item">The item whose readonly is being tested</param>
+        internal static void ThrowIfReadOnly(MetadataItem item)
+        {
+            Debug.Assert(item != null, "The given item is null");
+            if (item.IsReadOnly)
+            {
+                throw EntityUtil.OperationOnReadOnlyItem();
+            }
+        }
+
+        /// <summary>
+        /// Check to make sure the given item do have identity
+        /// </summary>
+        /// <param name="item">The item to check for valid identity</param>
+        /// <param name="argumentName">The name of the argument</param>
+        [Conditional("DEBUG")]
+        internal static void AssertItemHasIdentity(MetadataItem item, string argumentName)
+        {
+            Debug.Assert(!string.IsNullOrEmpty(item.Identity), "Item has empty identity.");
+            EntityUtil.GenericCheckArgumentNull(item, argumentName);
+        }
+        #endregion
+    }
+}