public String toString()
	{
		StringBuffer sb = new StringBuffer();
		sb.append( versions+": " );
		if ( parent != null )
		{
			sb.append("["+parent.id+":");
			sb.append( new String(parent.data) );
			sb.append( "]" );
		}
		else if ( children != null )
		{
			sb.append("{"+id+":");
			sb.append( new String(data) );
			sb.append( "}" );
			sb.append("; children=");
			for ( int i=0;i<children.size();i++ )
			{
				Pair p = children.get( i );
				sb.append(p.toString());
				if ( i < children.size()-1 )
					sb.append(",");
			}
		}
		else if ( data != null )
			sb.append( new String(data) );
		else
			sb.append("null");
		return sb.toString();
	}