/// <summary>
 /// Add <paramref name="newAppender"/> to the list of appenders of this
 /// Logger instance.
 /// </summary>
 /// <param name="newAppender">An appender to add to this logger</param>
 /// <remarks>
 /// Add <paramref name="newAppender"/> to the list of appenders of this
 /// Logger instance.
 /// <para>If <paramref name="newAppender"/> is already in the list of
 /// appenders, then it won't be added again.</para>
 /// </remarks>
 virtual public void AddAppender(IAppender newAppender)
 {
     if (newAppender == null)
     {
         throw new ArgumentNullException("newAppender");
     }
     lock (this)
     {
         if (m_aai == null)
         {
             m_aai = new log4net.helpers.AppenderAttachedImpl();
         }
         m_aai.AddAppender(newAppender);
     }
 }
		/// <summary>
		/// Adds an <see cref="IAppender" /> to the list of appenders of this
		/// instance.
		/// </summary>
		/// <param name="newAppender">The <see cref="IAppender" /> to add to this appender.</param>
		/// <remarks>
		/// <para>
		/// If the specified <see cref="IAppender" /> is already in the list of
		/// appenders, then it won't be added again.
		/// </para>
		/// </remarks>
		virtual public void AddAppender(IAppender newAppender) 
		{
			if (newAppender == null)
			{
				throw new ArgumentNullException("newAppender");
			}
			lock(this)
			{
				if (m_aai == null) 
				{
					m_aai = new log4net.helpers.AppenderAttachedImpl();
				}
				m_aai.AddAppender(newAppender);
			}
		}