UnityEditor.GUID.Empty C# (CSharp) Method

        public bool Empty()
        {
            return ((((this.m_Value0 == 0) && (this.m_Value1 == 0)) && (this.m_Value2 == 0)) && (this.m_Value3 == 0));
        }

 private void StopPreview()
 {
     if (!m_PreviewID.Empty())
     {
         VideoUtil.StopPreview(m_PreviewID);
     }
     m_PlayingClip = null;
     m_PreviewID   = kEmptyGUID;
 }