anchor.diff:          }).
   
   -type ejson() :: tuple(). % TODO Improve
  --type signing_method() :: 'rsa2048_sha1' | 'hmac_sha256'.
   
   %% ------------------------------------------------------------------
   %% API Function Definitions
  
positive.code: %%
  %% Send multiple messages
  %%
  -spec do_send_multi(#state{}, signing_method(), [node_ref()], ejson()) -> #state{}.
  do_send_multi(#state{addr_node_map = AddrNodeMap,
                       command_sock = Socket} = State,
                hmac_sha256 = Method, NodeRefs, Message) ->
  
negative.code: %%%
  %%% Send a message to a single node
  %%%
  -spec do_send(#state{}, pushy_signing_method(), node_ref(), ejson()) -> #state{}.
  do_send(#state{addr_node_map = AddrNodeMap,
                 command_sock = CommandSocket}=State,
          Method, NodeRef, Message) ->
  