code: func (v *TextView) AddChildInWindow(child IWidget, tp TextWindowType, xpos, ypos int) {
  	C.gtk_text_view_add_child_in_window(v.native(), child.toWidget(), C.GtkTextWindowType(tp), C.gint(xpos), C.gint(ypos))
  }
docs: // AddChildInWindow is a wrapper around gtk_text_view_add_child_in_window().