question: public static List < CompoundTag > writeInventory ( ItemStack [ ] items , int start ) { List < CompoundTag > out = new ArrayList < > ( ) ; for ( int i = 0 ; i < items . length ; i ++ ) { ItemStack stack = items [ i ] ; if ( stack != null ) { out . add ( writeItem ( stack , start + i ) ) ; } } return out ; }
target:  Write a full inventory (players, chests, etc.) to a compound list.