Question: what is a movement an actor in A Flag is Born involved with for years? 

<P0-S0> Marlon Brando Jr. (April 3, 1924 – July 1, 2004) was an American actor, film director and political activist. <P0-S1>  He is widely credited with bringing realism to film acting. <P0-S2>  He helped to popularize the Stanislavski system of acting, studying with Stella Adler in the 1940s. <P0-S3>  Brando was also an activist for many causes, notably the Civil Rights Movement and various Native American movements. <P0-S4>  Brando is widely known for his Academy Award-winning performances as Terry Malloy in "On the Waterfront" (1954) and Vito Corleone in "The Godfather" (1972), as well as his performances in "A Streetcar Named Desire" (1951), "Viva Zapata! <P0-S5> " (1952), "Julius Caesar" (1953), "The Wild One" (1953), "Guys and Dolls" (1955), "Sayonara" (1957), "Last Tango in Paris" (1972), and "Apocalypse Now" (1979). <SEP> <P1-S0> Salah Ameidan (born 1982) is a Saharawi long distance runner. <P1-S1>  He grew up in El Aiun. <P1-S2>  At the age of 12, he was recruited for the Moroccan running team and sent to Rabat to train. <P1-S3>  For ten years he participated in international races under the Moroccan flag. <P1-S4>  By 1999 he was the triple cross-country champion for Morocco, had won 2nd place in the Africa Championships and was two-time Arab World Champion. <P1-S5>  In 2004 during a race in France where he participated under the Moroccan flag, he raised the Saharawi flag above his head during the last few hundred metres of the race. <P1-S6>  Immediately after that he sought political asylum in France, as this action would likely have led to imprisonment in Morocco. <P1-S7>  Ameidan was imprisoned for a short period in 2009 after participating in a demonstration in El Aiun. <P1-S8>  Since 2004 he has been competing with a French team in competitions organized by the French Sport Federations, but as a Sahrawi athlete in international competitions. <P1-S9>  In 2013 a film, called "The Runner", was released about him by the Egyptian/Palestinian/British documentary film maker Saeed Taji Farouky. <SEP> <P2-S0>  With a cast including Paul Muni, Celia Adler and Marlon Brando, it opened on Broadway on September 4, 1946. <P2-S1> A Flag is Born is a 1946 play that advocated the creation of a homeland for the Jewish people in the ancient Land of Israel—at the time of the play's release Mandatory Palestine, under British administration. <P2-S2>  It was written by Ben Hecht and directed by Luther Adler, with music by Kurt Weill. <P2-S3>  "A Flag is Born" was produced by the American League for a Free Palestine, an organization headed by Hillel Kook (known in America by the anglicized name Peter Bergson), to raise money for Zionist causes. <SEP> <P3-S0> A Movement director is involved with actor movement in a variety of production settings that include theatre, television, film, opera and animation. <P3-S1>  Movement directors usually work closely with the director and the performers, collaborating with the creative team to realise the physical life of a work. <P3-S2>  They propose a physical language to performers and directors, and devise training methods or teach skills that will help facilitate a specific physical style. <P3-S3>  The movement director may create, or research and pass on, embodied information about etiquette, ethnicities (including proxemics, gestural language, social codes, etc.), a character’s condition (related to medical conditions within their historical context, and factors such as inebriation, pregnancy, etc.) and personal journey (ageing, etc.), as well as specialist movement (e.g. period dances, dexterity in falling, lifts and acrobatics, animal work, cross-gendered performance) or chorus work.