Question: What do Call Me Kuchu and The River have in common? 
Context: A delegate is a form of type-safe function pointer used by the Common Language Infrastructure (CLI).  Delegates specify a method to call and optionally an object to call the method on.  Delegates are used, among other things, to implement callbacks and event listeners.  A delegate object encapsulates a reference to a method.  The delegate object can then be passed to code that can call the referenced method, without having to know at compile time which method will be invoked. The River is a 1938 short documentary film which shows the importance of the Mississippi River to the United States, and how farming and timber practices had caused topsoil to be swept down the river and into the Gulf of Mexico, leading to catastrophic floods and impoverishing farmers.  It ends by briefly describing how the Tennessee Valley Authority project was beginning to reverse these problems. Rhinogobius carpenteri is a freshwater species of goby endemic to the Philippines.  It grows up to 5.9 cm SL, and is dull yellow-brown, whitish under the jaw, eyes blue, grayish fins with two silvery white anterior spines, silvery white anal fin rays, with the caudal fins shading to dusky at the tip.  Its common name in the Philippines is "kuchu".  The species was named for the co-collector of the cotypes, Mr. W. D. Carpenter.  In 1927, Albert William Christian Theodore Herre erected a new genus in the family Gobiidae, "Tukugobius" and moved "R. carpenteri" into it as the type species, but the genus was later rendered invalid. Broadcast call signs are call signs assigned as unique identifiers to radio stations and television stations.  While broadcast radio stations will often brand themselves with plain-text names, identities such as "cool FM", "rock 105" or "the ABC network" are not globally unique.  Another station in another city or country may (and often will) have a similar brand, and the name of a broadcast station for legal purposes is normally its internationally recognised ITU call sign.  Some common conventions are followed around the world. A missed call is a telephone call that is deliberately terminated by the caller before being answered by its intended recipient, in order to communicate a pre-agreed message without paying the cost of a call.  For example, a group of friends may agree that two missed calls in succession means "I am running late".  The practice is common in South Asia, the Philippines and Africa. Katherine Fairfax Wright is an American filmmaker and documentarian, best known as co-director with Malika Zouhali-Worrall of the 2012 film "Call Me Kuchu". Call signs in Europe is a code consisting of a three letter country code and a series of letters and numbers, used as unique identifiers for broadcasting and telecommunications.  These are not designated formally to all broadcast stations in Europe like they are in other parts of the world, but some broadcasters have developed their own makeshift call signs.  It is quite common that instead of regular call signs abbreviations of the stations' names are used (e.g. ARD, RTL in Germany, ORF in Austria, BBC, ITV or SKY in the United Kingdom, TF1 in France, TV3 in Spain, etc.).  In most of Europe, TV and radio stations have unique names, such as ProSieben in Germany, France 2 in France, Nova Television in Bulgaria, Antena 3 in Spain, etc. Sunset, also known as the Retreat Call, is a bugle call played in United Kingdom and British Commonwealth countries to signal the end of the official military day.  It uses a slightly different melody to the US Retreat bugle call.  In common with all bugle calls, it consists only of notes from a single overtone series.  This allows it to be playable on a bugle or equivalently on a trumpet without moving the valves. Malika Zouhali-Worrall is a documentary filmmaker of British and Moroccan descent, best known as one of the directors, with Katherine Fairfax Wright, of the 2012 award-winning film "Call Me Kuchu". Call Me Kuchu is a 2012 American documentary film directed by Malika Zouhali-Worrall and Katherine Fairfax Wright.  The film explores the struggles of the LGBT community in Uganda, focusing in part on the 2011 murder of LGBT activist David Kato.
Answer: documentary film