title: How to check if a key exists in a MemoryCache
body: <p>I need to check if a key is present in a MemoryCache. However there is no Keys collection or something similar available. </p>
  
  <p>I do not need the object associated with the key only a true or false if a certain key is present.</p>
  
  <p>I know I can try a .Get(key) but I do not need the object. Is this the only way?</p>