WIP extract variables from sspm objects
# S4 method for sspm_boundary
$(x, name)
# S4 method for sspm_discrete_boundary
$(x, name)
# S4 method for sspm_dataset
$(x, name)
# S4 method for sspm
$(x, name)
[sspm_...] An object from this package.
[character] The name of the column
The data.frame
matching the request.
if (FALSE) {
sspm_boundary$lat
sspm_dataset$biomass
}