code: public final void setProxy (@Nullable final HttpHost aProxy, @Nullable final Credentials aProxyCredentials)
    {
      m_aProxy = aProxy;
      m_aProxyCredentials = aProxyCredentials;
    }
docs: Set proxy host and proxy credentials.
  
  @param aProxy
  The proxy host to be used. May be <code>null</code>.
  @param aProxyCredentials
  The proxy server credentials to be used. May be <code>null</code>.
  They are only used if a proxy host is present! Usually they are of
  type {@link org.apache.http.auth.UsernamePasswordCredentials}.
  @since 8.8.0
  @see #setProxy(HttpHost)