commons-file/src/main/java/info/monitorenter/util/Entry.java
public K setValue(final K value) {
    final K ret = this.m_value;
    this.m_value = value;
    return ret;
  }
public K setValue(final K value) {
    final K ret = this.m_value;
    this.m_value = value;
    return ret;
  }
Sets a new value instance overwriting the old value which is returned.
<p>

You may use null. But you will get it back next call!
<p>

@see java.util.Map.Entry#setValue(Object)

@return the previous value instance.