code: function(domain, ip, options) {
  		var self = this;
  		var defaultName = this.defaultName;
  		var updateHost = function(host) {
  			host.domain = domain;
  			host.ip = ip;
  			typeof options.disabled !== 'undefined' ? host.disabled = options.disabled: '';
  			typeof options.note !== 'undefined' ? host.note = options.note: '';
  		};
  		ip = ip || '127.0.0.1';
  		options = options || {};
  		this._batchHost(function(hostsobject) {
  			groupName = options.groupName || defaultName;
  			var group = hostsobject[groupName] = hostsobject[groupName] || [];
  			for (var i = 0; i < group.length; i++) {
  				var host = group[i];
  				if ((host.domain === domain && host.ip === ip) || (host.domain === options.olddomain && host.ip === options.oldip)) {
  					if(!options.disabled) self._disableAllDomain(domain,hostsobject);
  					updateHost(host);
  					return hostsobject;
  				}
  			}
  			group.push({
  				ip: ip,
  				domain: domain,
  				disabled: !! options.disabled,
  				note: options.note || ''
  			});
  			return hostsobject;
  		});
  	}
docs: 设置一个domain