improve readability

src/Store.js

@@ -486,22 +486,23 @@ class Store {
   }
 
   async _addOperation (data, { onProgressCallback, pin = false } = {}) {
-    return this._opqueue.add(async () => {
+    async function addOperation () {
       if (this._oplog) {
         // check local cache?
         if (this.options.syncLocal) {
           await this.syncLocal()
         }
 
-        const entry = await this._oplog.append(data, this.options.referenceCount, pin)
+        const entry = await this._oplog.append(data, this.options.referenceCount)
         this._recalculateReplicationStatus(this.replicationStatus.progress + 1, entry.clock.time)
         await this._cache.set(this.localHeadsPath, [entry])
         await this._updateIndex()
         this.events.emit('write', this.address.toString(), entry, this._oplog.heads)
         if (onProgressCallback) onProgressCallback(entry)
         return entry.hash
       }
-    })
+    }
+    return this._opqueue.add(addOperation.bind(this))
   }
 
   _addOperationBatch (data, batchOperation, lastOperation, onProgressCallback) {