Laverne & Shirley is an American sitcom that ran on ABC from January 27, 1976, to May 10, 1983. It starred Penny Marshall as Laverne DeFazio and Cindy Williams as Shirley Feeney, single roommates who work as bottlecappers in a fictitious Milwaukee brewery called Shotz Brewery. Among others, the series was known for Marshall and Williams' physical comedy.
Fictional characters Laverne DeFazio and Shirley Feeney worked as bottlecappers in a fictitious Milwaukee brewery called Shotz Brewery for the entire run of the show Laverne & Shirley. 
This statement is neither definitely correct nor definitely incorrect because the information provided does not indicate whether or not the character were always bottlecappers, or whether the program showed them before they worked this job or after.  I don't think the model could make that distinction.