(function (window) {
  class ContractError extends Error {
    constructor(message) {
      super(message);
      this.name = "ContractError";
    }
  }

  function ContractAssert(cond, message) {
    if (!cond) throw new ContractError(message);
  }

  window.ContractError = ContractError;
  window.ContractAssert = ContractAssert;

  // EXTRA
  window.SMARTWEAVE_HOST = () => Deno.core.opAsync("op_smartweave_get_host");
})(this);