tariff-methods: S4 methods to calculate tariffs for given dancefloors
In C3S/GEMATariff: Calculate GEMA tariffs

The method GEMA_m_u_iii calculates GEMA tarifs as of 2012, GEMA_m_cd calculates the new tariffs as of 2014.

Calculate GEMA tariff M U-III

Calculate GEMA tariff U-T I (Musikauff<c3><bc>hrungen in Tanzlokalen)

Calculate GEMA tariff U-K I (Wiedergaben mit Musikern)

GEMA_m_cd(dancefloor, year = as.numeric(format(Sys.time(), "%Y")),
  discount = FALSE)

## S4 method for signature 'GEMA.dancefloor'
GEMA_m_cd(dancefloor,
  year = as.numeric(format(Sys.time(), "%Y")), discount = FALSE)

GEMA_m_u_iii(dancefloor, discount = FALSE)

## S4 method for signature 'GEMA.dancefloor'
GEMA_m_u_iii(dancefloor, discount = FALSE)

GEMA_u_t(liveclub, discount = FALSE)

## S4 method for signature 'GEMA.liveclub'
GEMA_u_t(liveclub, discount = FALSE)

GEMA_u_k(gig, byGross = TRUE, year = as.numeric(format(Sys.time(), "%Y")),
  discount = FALSE)

## S4 method for signature 'GEMA.gig'
GEMA_u_k(gig, byGross = TRUE,
  year = as.numeric(format(Sys.time(), "%Y")), discount = FALSE)

`year`	Integer. If between 2014 and 2021, the market entry reduction will be calculated. Set to a different year to disable.
`discount`	Logical, whether a reduction due to a global contract ("Gesamtvertrag") is eligable. As of now, a reduction of 20% is granted if this is set to `TRUE`.
`byGross`	Locical, whether calculations should be based on `gross` value instead of codeguests \times `admission`.
`obj`	An object of class `GEMA.dancefloor-class`.
`obj`	An object of class `GEMA.dancefloor-class`.
`discount`	Logical, whether a reduction due to a global contract ("Gesamtvertrag") is eligable. As of now, a reduction of 20% is granted if this is set to `TRUE`.
`obj`	An object of class `GEMA.liveclub-class`.
`discount`	Logical, whether a reduction due to a global contract ("Gesamtvertrag") is eligable. As of now, a reduction of 20% is granted if this is set to `TRUE`.
`obj`	An object of class `GEMA.gig-class`.
`year`	Integer. If between 2015 and 2022, the market entry reduction will be calculated. Set to a different year to disable.
`discount`	Logical, whether a reduction due to a global contract ("Gesamtvertrag") is eligable. As of now, a reduction of 20% is granted if this is set to `TRUE`.