UnityEditor.LightingWindow.DrawHelpGUI C# (CSharp) Method

        private void DrawHelpGUI()
        {
            Vector2 vector = EditorStyles.iconButton.CalcSize(EditorGUI.GUIContents.helpIcon);
            if (GUI.Button(GUILayoutUtility.GetRect(vector.x, vector.y), EditorGUI.GUIContents.helpIcon, EditorStyles.iconButton))
            {
                Help.ShowHelpPage("file:///unity/Manual/GlobalIllumination.html");
            }
        }