def map_search_params(search_params)
      Hash[search_params.map {|k, v| [key_map[k], v] }]
    end
def map_search_params(search_params)
      Hash[search_params.map {|k, v| [key_map[k], v] }]
    end
This takes a hash of search parameters, and modifies
 the hash to have the correct key types for the current RETS server