Function atk_sys::atk_text_get_text_before_offset

pub unsafe extern fn atk_text_get_text_before_offset(text: *mut AtkText,
                                                     offset: c_int,
                                                     boundary_type: AtkTextBoundary,
                                                     start_offset: *mut c_int,
                                                     end_offset: *mut c_int)
                                                     -> *mut c_char