'$schema' => "http://specs.example.com/message#",
'content' => "Hello world!"
$chainId = "JEKNVnkbo3jqSHT8tfiAKK4tQTFK7jbx8t18wEEnygya";
$chainLastHash = "3yMApqCuCjXDWPrbjfR5mjCPTHqFG8Pux1TxQrEM35jj";
$chain = new LTO\EventChain($chainId, $chainLastHash);
$chain->add(new Event($body))->signWith($account);