check_ages              Check list of age codes
check_areas             Check list of area codes
check_indicators        Check list of indicator codes
check_perc              Check list of percentiles
check_pop               Check list of population codes
check_years             Check list of years
download_wid            Download data from WID.world
environment             Get variables associated to a list of area
                        codes
get_data_variables      Get data associated to a list of variables
get_metadata_variables
                        Get metadata associated to a list of variables
