textview placeholder when using JNMentionTextView

[mohamedFalah]

I am using a class which implements UITextViewDelegate to add placeholder to Textview
https://tij.me/blog/adding-placeholders-to-uitextviews-in-swift/

the placeholder appear if nothing is written in text but when i start typing the placeholder does not go after implementing JNMentionTextView
also placeholder should appear if all text is deleted from text view but after the implementation of JNMentionTextView it does not