You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "In the screenplay Sweethearts, Victor Herbert's play was was used. What type of performance was this?" whose answer is “play within a play”.
Each document should contain about 30 words, and these documents should contain useful information.

Query: "Sweethearts" Victor Herbert play adaptation type
Useful Output:

Doc 1: The production in which the two stars are supposed to be appearing is actually Victor Herbert's 1913 operetta Sweethearts. While the movie's
Doc 2: LOONY's two-night revival of Victor Herbert's extravagantly tuneful “Sweethearts” rates as one of the plucky company's best outings. Sensitively
Doc 3: Herbert's 1913 Sweethearts had a silly plot reminiscent of the Savoy shows, but it did uniformly well on Broadway, on the road and in
Doc 4: "Sweethearts" is a 1938 American Technicolor musical romance film directed by W.S. Van Dyke. Starring Jeanette MacDonald and Nelson Eddy, it was the first
Doc 5: Modiste (1905), The Red Mill (1906), Naughty Marietta (1910), Sweethearts (1913) and Eileen (1917). After World War I, with the change of popular musical tastes