code: function deployFIFSRegistrar(deployer, tld) {
    var rootNode = getRootNodeFromTLD(tld);
  
    // Deploy the ENS first
    deployer.deploy(ENS)
      .then(() => {
        // Deploy the FIFSRegistrar and bind it with ENS
        return deployer.deploy(FIFSRegistrar, ENS.address, rootNode.namehash);
      })
      .then(function() {
        // Transfer the owner of the `rootNode` to the FIFSRegistrar
        return ENS.at(ENS.address).then((c) => c.setSubnodeOwner('0x0', rootNode.sha3, FIFSRegistrar.address));
      });
  }
docs: Deploy the ENS and FIFSRegistrar
  
  @param {Object} deployer truffle deployer helper
  @param {string} tld tld which the FIFS registrar takes charge of