+=item get_dids SELECTION
+
+Does several things, which is unfortunate. DID phone numbers are organized
+in a sort-of hierarchy: state, areacode, exchange, number. Or, for some
+vendors: state, region, number. But not always that, either.
+
+SELECTION is one or more field/value pairs specifying parts of the hierarchy
+that have already been selected. C<get_dids> will then return an arrayref of
+the possible values for the next selection level. Note that these are not
+actual DIDs except at the lowest level.
+
+Generally, 'state' alone will return an array of area codes or region names
+in the state.
+
+'state' and 'areacode' together will return an array of exchanges (NXX
+prefixes), or for some exports, an array of ratecenter names.
+
+'areacode' and 'exchange', or 'state' and 'ratecenter', or 'region' by itself
+will return an array of actual DID numbers.
+
+Passing 'tollfree' with a true value will override the whole hierarchy and
+return an array of tollfree numbers.
+
+=cut
+
+# no stub; can('get_dids') should return false by default
+