computer: new stateful 2

crates/brk_computer/src/grouped/price_percentiles.rs

@@ -94,8 +94,10 @@ impl Flushable for PricePercentiles {
         }
         Ok(())
     }
+}
 
-    fn safe_write(&mut self, exit: &Exit) -> Result<()> {
+impl PricePercentiles {
+    pub fn safe_write(&mut self, exit: &Exit) -> Result<()> {
         for vec in self.vecs.iter_mut().flatten() {
             if let Some(height_vec) = vec.height.as_mut() {
                 height_vec.safe_write(exit)?;