white space on top of viewpager in coordinatorlayout

Keywords´╝Ü android-viewpager android-coordinatorlayout android-collapsingtoolbarlayout android-nestedscrollview

Question: 

In the main layout i have a coordinatorlayout than its childs are appbarlayout and viewpager. in each page of viewpager i have an fragment that have nestedscrollview or recyclervew, my problem is that there is a white space in top of all fragments in each page of view pager:

<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="fill_vertical"
android:id="@+id/konta">

<android.support.design.widget.AppBarLayout
    android:id="@+id/smooth_app_bar_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/blue_200"
    android:minHeight="@dimen/mdSecondaryActionBarSize">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar_layout"
        android:layout_width="match_parent"
        android:layout_height="@dimen/app_bar_height"
        app:titleEnabled="false"
        app:layout_collapseMode="parallax"
        android:background="@android:color/transparent"
        app:layout_scrollFlags="scroll|snap">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="@dimen/toolbar_height"
            android:background="@android:color/transparent"
            app:layout_collapseMode="pin"
            app:layout_scrollFlags="scroll|enterAlways"
            app:navigationIcon="@drawable/ic_arrow_right" />
    </android.support.design.widget.CollapsingToolbarLayout>
    <android.support.design.widget.TabLayout
        android:layoutDirection="ltr"
        tools:targetApi="jelly_bean_mr1"
        android:id="@+id/tab_layout"
        android:layout_width="match_parent"
        android:layout_height="@dimen/tab_size"
        android:background="@android:color/transparent"
        app:tabIndicatorColor="@android:color/white" />

</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
    android:id="@+id/view_pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="fill_vertical"
    android:fitsSystemWindows="true"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>

Answers: