add 2 min request cache, remove a few unneeded semicolons

source/connector-mobilizon/front/session-cache.js

@@ -0,0 +1,24 @@
+import hash from './object-hash-wrapper'
+
+const MAX_AGE_IN_MS = 120000
+
+export class SessionCache {
+
+  static add(parameters, data) {
+    const key = hash(parameters)
+    const timestamp = Date.now()
+    const value = {
+      data,
+      timestamp,
+    }
+    sessionStorage.setItem(key, JSON.stringify(value))
+  }
+
+  static get(parameters) {
+    const key = hash(parameters)
+    const value = JSON.parse(sessionStorage.getItem(key))
+    if (value.timestamp && value.timestamp > Date.now() - MAX_AGE_IN_MS)
+      return value.data
+    return null
+  }
+}