class Geocoder::Lookup::Base

something else (like the URL before OAuth encoding).
timestamp, etc varies from one request to another, we need to use
request URL, but in cases where OAuth is used and the nonce,
Key to use for caching a geocoding result. Usually this will be the
#

def cache_key(query)
  base_query_url(query) + hash_to_query(cache_key_params(query))
end