title: List.Contains(item) with generic list of objects
body: <p>If you have a List how do you return the item if a specified property or collection of properties exists?</p>
  
  <pre><code>public class Testing
  {
      public string value1 { get; set; }
      public string value2 { get; set; }
      public int value3 { get; set; }
  }
  public class TestingList
  {
      public void TestingNewList()
      {
          var testList = new List&lt;Testing&gt;
                             {
                                 new Testing {value1 = "Value1 - 1", value2 = "Value2 - 1", value3 = 3},
                                 new Testing {value1 = "Value1 - 2", value2 = "Value2 - 2", value3 = 2},
                                 new Testing {value1 = "Value1 - 3", value2 = "Value2 - 3", value3 = 3},
                                 new Testing {value1 = "Value1 - 4", value2 = "Value2 - 4", value3 = 4},
                                 new Testing {value1 = "Value1 - 5", value2 = "Value2 - 5", value3 = 5},
                                 new Testing {value1 = "Value1 - 6", value2 = "Value2 - 6", value3 = 6},
                                 new Testing {value1 = "Value1 - 7", value2 = "Value2 - 7", value3 = 7}
                             };
  
          //use testList.Contains to see if value3 = 3
          //use testList.Contains to see if value3 = 2 and value1 = "Value1 - 2"
  
  
      }
  }
  </code></pre>