Question: What subject of Andy Warhol's film "Sleep" has sat in on  Bernadette Mayer's workshopts?

Context paragraphs:
San Diego Surf (film): San Diego Surf is a 1968 feature film directed by Andy Warhol and Paul Morrissey, and filmed in La Jolla, California in May 1968.  On June 3, 1968, Warhol was shot by Valerie Solanas, bringing work on the film to a halt.  In 1996, the Andy Warhol Foundation commissioned Morrissey to "finish editing the film based on Warhol's notes".

Bernadette Mayer: Bernadette Mayer (born May 12, 1945) is an American poet, writer, and visual artist associated with both the Language poets and the New York School.  Mayer's record-keeping and use of stream-of-consciousness narrative are two trademarks of her writing, though she is also known for her work with form and mythology.  In addition to the influence of her textual-visual art and journal-keeping, Mayer's poetry is widely acknowledged as some of the first to speak accurately and honestly about the experience of motherhood.  Mayer edited the journal "0 TO 9" with Vito Acconci, and, until 1983, United Artists books and magazines with Lewis Warsh.  Mayer taught at the New School for Social Research, where she earned her degree in 1967, and, during the 1970s, she led a number of workshops at the Poetry Project at St. Mark's Church in New York.  From 1980 to 1984, Mayer served as director of the Poetry Project, and her influence in the contemporary avant-garde is felt widely, with writers like Kathy Acker, Charles Bernstein, John Giorno, and Anne Waldman having sat in on her workshops.  Mayer was a 2015 Guggenheim Fellowship Recipient and received a National Book Critics Circle Nomination for her most recent book, 2016's "Works and Days".

Exploding Plastic Inevitable: The Exploding Plastic Inevitable, sometimes simply called Plastic Inevitable or EPI, was a series of multimedia events organized by Andy Warhol between 1966 and 1967, featuring musical performances by The Velvet Underground and Nico, screenings of Warhol's films, and dancing and performances by regulars of Warhol's Factory, especially Mary Woronov and Gerard Malanga.  "Andy Warhol's Exploding Plastic Inevitable" is also the title of an 18-minute film by Ronald Nameth with recordings from one week of performances of the shows which were filmed in Chicago, Illinois, in 1966.  In December 1966 Warhol included a one-off magazine called "The Plastic Exploding Inevitable" as part of the "Aspen" No. 3 package.

Beautiful Darling: Beautiful Darling: The Life and Times of Candy Darling, Andy Warhol Superstar is a 2010 feature-length documentary film about Candy Darling, the transgender pioneer, actress and Andy Warhol Superstar.  The film was written and directed by James Rasin and features Chloë Sevigny as "the voice of Candy Darling", reading from Candy's private diaries and letters.  Patton Oswalt voices Andy Warhol and Truman Capote.  Louis Durra composed the score.

The Andy Warhol Story: The Andy Warhol Story (1966) is an underground film directed by Andy Warhol with cinematography by Paul Morrissey, and starring Edie Sedgwick and Rene Ricard (as Andy Warhol).

Empire (1964 film): Empire is a 1964 American black and white silent film written, produced, and directed by Andy Warhol.  It consists of eight hours and five minutes of continuous slow motion footage of the Empire State Building in New York City.  Abridged showings of the film were never allowed, and supposedly the unwatchability of the film was an important part of the reason the film was created.  However, a legitimate Italian VHS produced in association with the Andy Warhol Museum in 2000 contains only an extract of 60 minutes.  Its use of the long take "in extremis" is an extension of Warhol's earlier work the previous year with "Sleep".  Warhol employed Rob Trains to be the projectionist for a screening of the film.  Trains miscalculated and mixed the order and speed of the reels for the eight-hour movie.  After a positive review in "The New York Times", Warhol actually liked the "mistake" and employed Trains for the entire summer.

John Warhola: John Warhola (May 31, 1925 – December 24, 2010) played a pivotal role in maintaining the legacy of his younger brother, pop artist Andy Warhol, assigned responsibility by their father on his deathbed to ensure that Andy attended college and serving as a trustee of the Andy Warhol Foundation for the Visual Arts after his brother's death in 1987.  Warhola oversaw the establishment of The Andy Warhol Museum in Pittsburgh and the Andy Warhol Museum of Modern Art in Medzilaborce, Slovakia.

I Shot Andy Warhol: I Shot Andy Warhol is a 1996 American-British independent film about the life of Valerie Solanas and her relationship with the artist Andy Warhol.  The film marked the debut of Canadian director Mary Harron.  The film stars Lili Taylor as Valerie, Jared Harris as Andy Warhol, and Martha Plimpton as Valerie's friend Stevie.  Stephen Dorff plays Warhol superstar Candy Darling.  John Cale of The Velvet Underground wrote the film's score despite protests from former band member Lou Reed.  Yo La Tengo plays an anonymous band that is somewhat reminiscent of the group.

John Giorno: John Giorno (born December 4, 1936) is an American poet and performance artist.  He founded the not-for-profit production company Giorno Poetry Systems and organized a number of early multimedia poetry experiments and events, including "Dial-A-Poem".  He became prominent as the subject of Andy Warhol's film "Sleep" (1963).  He is also an AIDS activist and fundraiser, and a long-time practitioner of the Nyingma tradition of Tibetan Buddhism.

Green Coca-Cola Bottles: Green Coca-Cola Bottles is a 1962 painting by Andy Warhol that depicts numerous Coca-Cola bottles.  Andy Warhol’s painting “Green Coca-Cola Bottles” attempted to take a mainstream item and converted it into a piece of art.  Warhol’s piece was a hybrid craft that is to say that he utilized a silkscreen technique, which mechanicalized some aspects of the painting, but also kept it so that he had to put in some of his individualized “unevenness” across the painting, to reel in the human aspect.  The painting engenders an optimistic message for the American public, which is best described in Warhol’s own words, “What’s grand about this country is that America started the tradition where the richest consumers buy essentially the same thing as the poorest... you can know that the President drinks Coke, Liz Taylor drinks Coke, and, just think, you can drink Coke, too.  A Coke is a Coke, and no amount of money can get you a better Coke.”  Here Warhol goes to show that the democratic equality, which allowed the birth of a uniformly governed consumerist mindset, has given them an equal satiating medium.  With respect to its artistic merits, Warhol’s painting utilizes repetitive imagery in the shape of hundred and twelve almost identical bottles, evoking a sense of mechanicalization which overlaps his former usage of mass culture objects.  The widespread display of advertisement flooded the American public during the sixties, and Warhol had been successful in mapping it onto his canvas, no wonder it is considered one of Warhol’s masterpieces.

Supporting paragraphs: Bernadette Mayer John Giorno
Answer: John Giorno