wip fix train

store/src/board.rs

@@ -153,6 +153,10 @@ impl Board {
             .unsigned_abs()
     }
 
+    pub fn to_vec(&self) -> Vec<i8> {
+        self.positions.to_vec()
+    }
+
     // maybe todo : operate on bits (cf. https://github.com/bungogood/bkgm/blob/a2fb3f395243bcb0bc9f146df73413f73f5ea1e0/src/position.rs#L217)
     pub fn to_gnupg_pos_id(&self) -> String {
         // Pieces placement -> 77bits (24 + 23 + 30 max)