My Layout contains a Collapsible toolbar a tab and a view pager...
I placed listview wraped in a NestedScrollView but this cant collapse my toolbar, I tried replacing it with RecyclerView still layout cant collapse.
I tried placing many 20 buttons vertically and this is able to collapse the toolbar 
I have tried several examples on github and several solutions on stackoverflow but all have proved futile
Much will be appreciated if am able to get a solution

```
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.design.widget.AppBarLayout
    android:id="@+id/appbar"
    android:layout_width="match_parent"
    android:layout_height="400dp"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_scrollFlags="scroll|exitUntilCollapsed">

             <ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
app:layout_collapseMode="parallax"
app:layout_collapseParallaxMultiplier="0.9"
android:src="@drawable/babe" />

        <android.support.design.widget.TabLayout
            android:id="@+id/tab_layout"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:layout_gravity="bottom"
            android:background="#ffffff"
            app:tabTextColor="#03A9F4"
            app:layout_collapseMode="pin"
            app:tabSelectedTextColor="#0288D1"
            app:tabContentStart="72dp" />

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="@null"
            app:layout_scrollFlags="scroll|enterAlways"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            app:layout_collapseMode="parallax" />

    </android.support.design.widget.CollapsingToolbarLayout>

</android.support.design.widget.AppBarLayout>

<android.support.v4.view.ViewPager
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" />

</android.support.design.widget.CoordinatorLayout> 

```

Fragment\_one with the listView

```
<android.support.v4.widget.NestedScrollView         
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
android:fillViewport="true" >

<ListView
    android:id="@+id/profilestatus_listview"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:cacheColorHint="@null"
    android:divider="#03A9F4"
    android:dividerHeight="1dp" />

</android.support.v4.widget.NestedScrollView>

```

Fragment\_two with Recycler\_View

```
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="500dp"
android:fillViewport="true"
app:layout_behavior="@string/appbar_scrolling_view_behavior">

 <android.support.v7.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"/>

</android.support.v4.widget.NestedScrollView>

```

Dummy\_Fragment which contains the buttons and it is able to collapse the toolbar

```
<android.support.v4.widget.NestedScrollView 
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
android:fillViewport="true" >

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="YO YO"
    />

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="YO YO"
    />

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="YO YO"
    />

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="YO YO"
    />

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="YO YO"
    />

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="YO YO"
    />

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="YO YO"
    />

</ListView>

</android.support.v4.widget.NestedScrollView>

```

All help will be appreciated...Thanks