anchor.diff:                          ?TAG_EXPIRES
                       end
       }}.
  -
   
   %%% Note to the reader!
   %%%
  
positive.code:                     | [{replica(), node()}],
                  url_cache :: 'false' | gb_set()}).
  
  % THOUGHT: Eventually we want to partition tag keyspace instead
  % of using a single global keyspace. This can be done relatively 
  % easily with consistent hashing: Each tag has a set of nodes 
  
negative.code: validate_urls(Urls) ->
      [] == (catch lists:flatten([[1 || X <- L, not is_binary(X)] || L <- Urls])).
  
  % Put transaction:
  % 1. choose nodes
  % 2. multicall nodes, send TagData -> receive temporary file names
  