anchor.diff:  
   
   handle_find_req(#httpd{method='POST'}=Req, Db) ->
  +    chttpd:validate_ctype(Req, "application/json"),
       {ok, Opts0} = mango_opts:validate_find(chttpd:json_body_obj(Req)),
       {value, {selector, Sel}, Opts} = lists:keytake(selector, 1, Opts0),
       {ok, Resp0} = start_find_resp(Req),
  
positive.code: %% deleted, but an error will be thrown for the current ddoc id.
  handle_index_req(#httpd{method='POST', path_parts=[_, <<"_index">>,
          <<"_bulk_delete">>]}=Req, Db) ->
      {ok, Opts} = mango_opts:validate_bulk_delete(chttpd:json_body_obj(Req)),
      Idxs = mango_idx:list(Db),
      DDocs = get_bulk_delete_ddocs(Opts),
  
negative.code: 
  
  handle_explain_req(#httpd{method='POST'}=Req, Db) ->
      chttpd:validate_ctype(Req, "application/json"),
      {ok, Opts0} = mango_opts:validate_find(chttpd:json_body_obj(Req)),
      {value, {selector, Sel}, Opts} = lists:keytake(selector, 1, Opts0),
      Resp = mango_crud:explain(Db, Sel, Opts),
  