added function to verify if type view is header

app/src/main/java/chat/rocket/android/widget/DividerItemDecoration.kt

@@ -8,6 +8,7 @@ import android.view.View
 import androidx.annotation.DrawableRes
 import androidx.core.content.ContextCompat
 import androidx.recyclerview.widget.RecyclerView
+import chat.rocket.android.chatrooms.adapter.RoomsAdapter
 
 /**
  * Adds a default or custom divider to specific item views from the adapter's data set.
@@ -56,6 +57,9 @@ class DividerItemDecoration() : RecyclerView.ItemDecoration() {
             if (isLastView(child, parent))
                 continue
 
+            if (isViewTypeHeader(child, parent))
+                continue
+
             val params = child.layoutParams as RecyclerView.LayoutParams
 
             val bottom = child.bottom + params.bottomMargin
@@ -70,4 +74,9 @@ class DividerItemDecoration() : RecyclerView.ItemDecoration() {
         val position = parent.getChildAdapterPosition(view)
         return position == parent.adapter?.itemCount?.minus(1) ?: false
     }
+
+    private fun isViewTypeHeader(view: View, parent: RecyclerView): Boolean {
+        val position = parent.getChildViewHolder(view).itemViewType
+        return position == RoomsAdapter.VIEW_TYPE_HEADER
+    }
 }
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