TaskGroup.swift

func getDocuments(range: Range<Int>) async throws -> [Data] {
    // 1.
    let documents = try await withThrowingTaskGroup(of: Data.self, returning: [Data].self,body: { group -> [Data] in
        // 2.
        for i in range {
            group.addTask(priority: .high, operation: { () -> Data in
                return try await getDocument(fileName: "Document-\(i)")
            })
        }
        
        var documents = [Data]()
        // 3.
        for try await document in group {
            documents.append(document)
        }
        // 4.
        return documents
    })
    
    return documents
}