added function aggregating multiple ticker data

src/corporate/helpers.rs

@@ -49,4 +49,12 @@ pub fn detect_changes(old: &CompanyEvent, new: &CompanyEvent, today: &str) -> Ve
     // Add similar for revenue if applicable
 
     changes
+}
+
+pub fn price_key(p: &CompanyPrice) -> String {
+    if p.time.is_empty() {
+        format!("{}|{}", p.ticker, p.date)
+    } else {
+        format!("{}|{}|{}", p.ticker, p.date, p.time)
+    }
 }