add_area_code           Get area codes from area names
add_area_name           Get area names from area codes
add_item_cbs_code       Get commodity balance sheet item codes from
                        item names
add_item_cbs_name       Get commodity balance sheet item names from
                        item codes
add_item_prod_code      Get production item codes from item names
add_item_prod_name      Get production item names from item codes
build_supply_use        Supply and use tables
expand_trade_sources    Trade data sources
get_bilateral_trade     Bilateral trade data
get_faostat_data        Scrapes activity_data from FAOSTAT and slightly
                        post-processes it
get_feed_intake         Livestock feed intake
get_primary_production
                        Primary items production
get_primary_residues    Crop residue items
get_processing_coefs    Processed products share factors
get_wide_cbs            Commodity balance sheet data
items_cbs               Commodity balance sheet items
items_prod              Primary production items
linear_fill             Fill gaps by linear interpolation, or carrying
                        forward or backward.
polities                Polities
proxy_fill              Fill gaps using a proxy variable
sum_fill                Fill gaps summing the previous value of a
                        variable to the value of another variable.
whep_inputs             External inputs
whep_list_file_versions
                        Input file versions
whep_read_file          Download, cache and read files
