promiseValue = {
let val = Promise.all([d3.csv("https://raw.githubusercontent.com/eyssette/frise-philo/main/data/philosophers-1.csv"),
d3.csv("https://raw.githubusercontent.com/eyssette/frise-philo/main/data/philosophers-2.csv"),
d3.csv("https://raw.githubusercontent.com/eyssette/frise-philo/main/data/philosophers-3.csv"),])
.then(files => (d3.merge(files)))
return () => val
}