code: function getDefaultProvider(network) {
      if (network == null) {
          network = 'homestead';
      }
      var n = utils.getNetwork(network);
      if (!n || !n._defaultProvider) {
          errors.throwError('unsupported getDefaultProvider network', errors.UNSUPPORTED_OPERATION, {
              operation: 'getDefaultProvider',
              network: network
          });
      }
      return n._defaultProvider(providers);
  }
docs: ////////////////////// Helper Functions