code: func (ctr *rowConstructor) SpaceBeginRatio(widget_count int) {
  	layout := ctr.win.layout
  	panelLayout(ctr.win.ctx, ctr.win, ctr.height, widget_count, 0)
  	layout.Row.Type = layoutDynamicFree
  
  	layout.Row.Ratio = nil
  	layout.Row.ItemWidth = 0
  	layout.Row.ItemRatio = 0.0
  	layout.Row.ItemOffset = 0
  	layout.Row.Filled = 0
  }
docs: // Starts new row that will contain widget_count widgets.
  // The size and position of widgets inside this row will be specified
  // by callling LayoutSpacePushRatio.