FIRMessaging Delegate Error
<p>I tried to add FIRMessagingDelegate but Xcode gives an error </p>

<p><code>Cannot find protocol declaration for FIRMessagingDelegate.</code> </p>

<p>I imported FirebaseMessaging and it gives no errors. I checked pods and it seems fine.</p>

<pre><code>Installing Firebase (3.2.1)
Using FirebaseAnalytics (3.2.0)
Using FirebaseInstanceID (1.0.6)
Installing FirebaseMessaging (1.1.0)
</code></pre>

<p>How I try to implement;</p>

<pre><code>#import &lt;UIKit/UIKit.h&gt;
#import &lt;UserNotifications/UserNotifications.h&gt;
#import &lt;MessageUI/MessageUI.h&gt;

#if defined(__IPHONE_10_0) &amp;&amp; __IPHONE_OS_VERSION_MAX_ALLOWED &gt;= __IPHONE_10_0
@import UserNotifications;
#endif

@import Firebase;
@import FirebaseInstanceID;
@import FirebaseMessaging;

@interface AppDelegate : UIResponder &lt;UIApplicationDelegate, UNUserNotificationCenterDelegate, FIRMessagingDelegate&gt;
</code></pre>

<p>I could not find any solution, what could be the reason for error?</p>