Creates superset with yield curves and future contracts indicating the terms that match with futures contracts maturities.
Examples
if (FALSE) { # \dontrun{
fut <- futures_get(Sys.Date() - 1)
yc <- yc_get(Sys.Date() - 1)
yc_superset(yc, fut)
yc_usd <- yc_usd_get(Sys.Date() - 1)
yc_usd_superset(yc_usd, fut)
yc_ipca <- yc_ipca_get(Sys.Date() - 1)
yc_ipca_superset(yc_ipca, fut)
} # }