title: C# is it possible to customise/override a class keeping its class name?
body: <p>If I have a class namespaceX.classA which uses namespaceX.classB is it possible to customise/overide/extend classB without breaking ClassA by using the same namespace (?) and class name? If so please could you explain how I go about doing this? </p>
  
  <p>Example extend by adding methods to ColumnHeaderCollection without breaking ListView</p>