# in IDE
# enable listening for incoming debug connections (if not enabled already)
# open "core/kernel/utility/temp_handler.php" for editing
# put a breakpoint on $ids = $this->DoCopyTempToOriginal($this->Tables, null, $master_ids); line in "\kTempTablesHandler::SaveEdit" method
# open regular browser window
# login to Admin Console
# go to {nav Website & Content > Labels & Phrases} section
# open 2 phrases for editing (remember the IDs, e.g. 15 and 36)
# enable debugging (the bug icon in the toolbar)
# press "Save" button
# continue to next test plan item only, when debugger has stopped at above created breakpoint
# in the database
# open "Semaphores" table
# locate entry matching session id from regular browser window
# remember which ID is written after comma in "MainIDs" column
# open private browser window
# login to Admin Console
# go to {nav Website & Content > Labels & Phrases} section
# open 1 phrase for editing (with ID remembered before)
# press "Save" button
# confirm, that after ~30 seconds of waiting instead of saving you'll get popup about concurrent Save attempt