Issue 351: Reimplement OAuth2 - Step 2 (Auth PCL - only data types)

Src/GoogleApis/Apis/Util/Utilities.cs

 /*
 Copyright 2010 Google Inc
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
 
 http://www.apache.org/licenses/LICENSE-2.0
 
 Unless required by applicable law or agreed to in writing, software
@@ skipping 25 matching lines @@
 {
 if (obj == null)
 {
 throw new ArgumentNullException(paramName);
 }
 }
 
 /// <summary>
 /// Throws an <seealso cref="System.ArgumentNullException"/> if the stri
ng is <c>null</c> or empty.
 /// </summary>
+/// <returns>The original string</returns>
 internal static string ThrowIfNullOrEmpty(this string str, string paramN
ame)
 {
 if (string.IsNullOrEmpty(str))
 {
 throw new ArgumentException("Parameter was empty", paramName);
 }
 return str;
 }
 
 /// <summary>Returns <c>true</c> in case the enumerable is <c>null</c> o
r empty. </summary>
@@ skipping 44 matching lines @@
 var enumType = o.GetType();
 FieldInfo field = enumType.GetField(o.ToString());
 StringValueAttribute attribute = field.GetCustomAttribute<String
ValueAttribute>();
 return attribute != null ? attribute.Text : o.ToString();
 }
 
 return o.ToString();
 }
 }
 }