docs: function ENS (provider, address, Web3js) {
    if (Web3js !== undefined) {
      Web3 = Web3js;
    }
    if (!!/^0\./.exec(Web3.version || (new Web3(provider)).version.api)) {
      return utils.construct(ENS_0, [provider, address]);
    } else {
      return utils.construct(ENS_1, [provider, address]);
    }
  }