public S2LatLng(S2Point p){
  this(Math.atan2(p.z,Math.sqrt(p.x * p.x + p.y * p.y)),Math.atan2(p.y,p.x));
}

public S2LatLng ( S2Point p ) { this ( Math . atan2 ( p . z , Math . sqrt ( p . x * p . x + p . y * p . y ) ) , Math . atan2 ( p . y , p . x ) ) ; }
convert a point ( not necessarily normalized ) to an s2latlng . todo ( dbeaumont ) : make this a static factory method ( frompoint ( ) ? ) .
