Question: What channel, owned and operated by Turner Broadcasting System Europe, had a sister station that closed 1 April 2014?

Context paragraphs:
Cartoon Network Arabic: Cartoon Network Arabic (Arabic: كرتون نتورك بالعربية‎ ‎ ) is a free-to-air satellite children's channel that is broadcast for a pan-Arab audience in the Middle East and North Africa region (excluding Israel, Iran, Turkey and Cyprus), and it is one of two Arabic-language versions of Cartoon Network, the other being an HD pay TV channel on beIN and additional providers called Cartoon Network MENA which is available in both English and Arabic.  The channel was launched on October 10, 2010 at 10:10 AM GST, with the channel's launch coinciding with the opening of Turner Broadcasting System Europe's offices in Dubai Media City.

Cartoon Network (Portugal): Cartoon Network, commonly abbreviated as CN, is a Portuguese digital cable and satellite television channel launched on December 3, 2013 and owned by Turner Broadcasting System Europe (a semi-autonomous unit of Time Warner).  Currently, Cartoon Network is the second most-watched kids and teens' channel in Portugal, recently surpassing Canal Panda and is now only behind Disney Channel.

Cartoon Network (Central and Eastern Europe): Cartoon Network CEE (also known as Cartoon Network Czech Republic, Cartoon Network Hungary and Cartoon Network Romania) is a children's channel broadcasting to people in Czech Republic, in Hungary, in Moldova, in Romania and in Slovakia.  The channel was launched along with the Romanian and Polish feed.  The channel is owned by Turner Broadcasting System Europe.  The channel also carried a Toonami programming block.  On April 1, 2015, Cartoon Network started broadcasting 24 hours a day in Hungary.  Hungary was the last country to get Cartoon Network timeshared with TCM.  On August 8, 2016, Cartoon Network Central Eastern Europe started to air Check It 4.0 bumpers and idents (alongside existing Check It 1.0 and Check It 3.0 branding).  On September 20, 2017, a Czech sub-feed was launched.

CNX (TV channel): CNX (or sometimes known as Cartoon Network Extreme) was a channel operated by Turner Broadcasting System Europe in the UK and Ireland between 2002 and 2003.  It was aimed at a male audience, with daytime programming aimed at older children and teenagers (predominantly 12–18 years of age), and evening programming aimed at older teenagers and young adults (the 17-34 demographic).  The channel was carried in the 'Entertainment' section of the Sky programme guide, and was also available on cable.

Boing (Africa): Boing is an African channel operated by Turner Broadcasting System Europe that launched on May 30, 2015.  The channel airs programming that is no longer transmitted by the African versions of some networks like the European versions, especially the French version in particular.

Cartoon Network (Poland): Cartoon Network Poland is a Polish language cartoon channel broadcasting to people in Poland.  The channel launched on 1 September 1998 on 12:00 am local time.  Since 1 March 2007, it's been broadcast 24 hours a day.  On 30 September 2002 the channel began to air in Hungary and Romania.  On 1 October 2008 a separate channel was created for Hungary & Romania.  Both are transmitted from Warsaw.  There was previously a Polish, Romanian, Hungarian and English audio track available.  Currently there's only a Polish and English audio track.  The channel is owned by Turner Broadcasting System Europe.  The channel also carried a Toonami programming block.The channel works with some Polish dubbing studios: Studio Sonica, Start International Polska, SDI Media Polska, Master Film and Studio Genetix Film Factory.  On 1 September 2016, Cartoon Network Poland re-branded using graphics from the Check It 4.0 branding package.

Cartoon Network (UK &amp; Ireland): Cartoon Network (commonly abbreviated as CN) is a British television channel available on Sky, Virgin Media, Smallworld Cable, TalkTalk Plus TV, UPC Ireland and TVPlayer (When subscribed to TVPlayer).  The channel is owned and operated by Turner Broadcasting System Europe (a semi-autonomous unit of Time Warner).

Cartoon Network Too: Cartoon Network Too was a British TV network created by Turner Broadcasting.  CN Too is the sister station of Cartoon Network, and it often aired programmes a while after they are shown on the main Cartoon Network.  During the daytime, it usually aired some action-adventure programming such as "" and "".  During overnight hours, usually between midnight and 06:00, it also aired some shows which are no longer being produced, and are no longer in high demand (i.e. "Skatoony").  Cartoon Network Too was closed on 1 April 2014.

Boomerang (Germany): Boomerang is German television channel broadcasting to children in Germany, Switzerland and Austria.  It was launched on June 1, 2006.  It is owned by Turner Broadcasting System Europe.

Turner Broadcasting System Russia: Turner Broadcasting System Russia is Turner Broadcasting System Europe's division in Russia, based in Moscow.

Supporting paragraphs: Cartoon Network Too Cartoon Network (UK &amp; Ireland)
Answer: Cartoon Network