code: @Override
      public boolean contains(Object key)
      {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              Tr.entry(tc, "contains", key);
  
          Bucket bucket = getBucketForKey(key);
  
          Element element = null; // d173022.12
          if (bucket != null) // d739870
          {
              synchronized (bucket)
              {
                  element = bucket.findByKey(key);
              } // d173022.12
          }
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              Tr.exit(tc, "contains", new Boolean(element != null));
  
          return element != null;
      }
docs: Check whether or not there is an object in the cache associated with
  the specified key. If such an object does exist it's pinned state
  is not affected. <p>
  
  @param key key to check for in the cache.
  
  @return true if there is an object in the cache associated with the
  specified key, false otherwise.