question: public static long firsttick ( GeoTimeSerie gts ) { if ( isBucketized ( gts ) ) { return gts . lastbucket - ( gts . bucketcount - 1 ) * gts . bucketspan ; } else { long firsttick = Long . MAX_VALUE ; if ( gts . sorted && gts . values > 0 ) { if ( ! gts . reversed ) { firsttick = gts . ticks [ 0 ] ; } else { firsttick = gts . ticks [ gts . values - 1 ] ; } } else { for ( int i = 0 ; i < gts . values ; i ++ ) { if ( gts . ticks [ i ] < firsttick ) { firsttick = gts . ticks [ i ] ; } } } return firsttick ; } }
target:  Return the first tick in the GTS instance.