code: public final AbstractItemLink get(final long key) {
          AbstractItemLink link = null;
          int i = _indexOfKey(key);
          synchronized (_getLock(i)) {
              Entry entry = _entry[i];
              while (null == link && null != entry) {
                  if (key == entry.id) {
                      link = entry.link;
                  } else {
                      entry = entry.next;
                  }
              }
          }
          return link;
      }
docs: Returns the AbstractItemLink to which the specified key is mapped in this map
  or <tt>null</tt> if the map contains no mapping for this key.
  
  @param   key the key whose associated value is to be returned.
  @return  the value to which this map maps the specified key, or
  <tt>null</tt> if the map contains no mapping for this key.
  @see #put(long, com.ibm.ws.sib.msgstore.cache.links.AbstractItemLink)