question: public final Sector union ( Sector that ) { if ( that == null ) return this ; Angle minLat = this . minLatitude ; Angle maxLat = this . maxLatitude ; Angle minLon = this . minLongitude ; Angle maxLon = this . maxLongitude ; if ( that . minLatitude . degrees < this . minLatitude . degrees ) minLat = that . minLatitude ; if ( that . maxLatitude . degrees > this . maxLatitude . degrees ) maxLat = that . maxLatitude ; if ( that . minLongitude . degrees < this . minLongitude . degrees ) minLon = that . minLongitude ; if ( that . maxLongitude . degrees > this . maxLongitude . degrees ) maxLon = that . maxLongitude ; return new Sector ( minLat , maxLat , minLon , maxLon ) ; }
target:  Returns a new sector whose angles are the extremes of the this sector and another. The new sector's minimum latitude and longitude will be the minimum of the two sectors. The new sector's maximum latitude and longitude will be the maximum of the two sectors. The sectors are assumed to be normalized to +/- 90 degrees latitude and +/- 180 degrees longitude. The result of the operation is undefined if they are not.