public static void closeQuietly(Selector selector) {
        if (selector != null) {
            try {
                selector.close();
            } catch (IOException ioe) {
                // ignored
            }
        }
    }
Unconditionally close a <code>Selector</code>.
<p>
Equivalent to {@link Selector#close()}, except any exceptions will be ignored.
This is typically used in finally blocks.
<p>
Example code:
<pre>
  Selector selector = null;
  try {
      selector = Selector.open();
      // process socket

  } catch (Exception e) {
      // error handling
  } finally {
      IOUtils.closeQuietly(selector);
  }
</pre>

@param selector the Selector to close, may be null or already closed
@since 2.2
pay-java-common/src/main/java/com/egzosn/pay/common/util/IOUtils.java