Returns the full request url for the given epidata_call
request_url(epidata_call, format_type = "classic", fields = NULL)
For request_url
: string containing the URL
an instance of epidata_call
format to return one of classic,json,csv
a list of epidata fields to return, or NULL to return all fields (default) e.g. c("time_value", "value") to return only the time_value and value fields or c("-direction") to return everything except the direction field