code: public T find(String key, Object val) {
          return find(key, val, null);
      }
docs: Returns the object identified by the specified key/value pair if it is currently
  in memory in the cache. Just because this value returns <code>null</code> does
  not mean the object does not exist. Instead, it may be that it is simply not
  cached in memory.
  @param key they unique identifier attribute on which you are searching
  @param val the value of the unique identifier on which you are searching
  @return the matching object from the cache