Set ALVtree table for first display

* Add following code to 'STATUS_0100'(PBO module)
*------------------------------------------------*
* Create empty ALVtree control ready for first display
  PERFORM create_empty_alvtree_control.


* Add following code to 'Z......F01' INCLUDE
*-------------------------------------------*
*&-------------------------------------------------------------*
*&      Form  CREATE_EMPTY_ALVTREE_CONTROL
*&-------------------------------------------------------------*
*       Create empty tree control
*--------------------------------------------------------------*
FORM create_empty_alvtree_control.
* Create emty tree-control
  CLEAR: it_emptytab.
  REFRESH: it_emptytab.
  CALL METHOD gd_tree->set_table_for_first_display
     EXPORTING
               is_hierarchy_header  = gd_hierarchy_header
               it_list_commentary   = gd_report_title
               i_logo               = gd_logo
*               i_background_id      = 'ALV_BACKGROUND'
               i_save               = 'A'
               is_variant            = gd_variant
     CHANGING
               it_outtab            =  it_emptytab      "Must be empty
               it_fieldcatalog      =  gd_fieldcat.

ENDFORM.                    " CREATE_EMPTY_ALVTREE_CONTROL