code: function(domain, ip, groupName, target_groupName) {
  		this._batchHost(function(hostsobject) {
  			var group = hostsobject[groupName];
  			var t_group = hostsobject[target_groupName] = hostsobject[target_groupName] || [];
  			if (group) {
  				var host, move, i;
  				//目标分组里是否存在该条host，若存在则不作处理。
  				for (i = 0; i < t_group.length; i++) {
  					host = t_group[i];
  					if (host.domain === domain && host.ip === ip) {
  						return false;
  					}
  				}
  				for (i = 0; i < group.length; i++) {
  					host = group[i];
  					if (host.domain === domain && host.ip === ip) {
  						t_group.push(host);
  						group.splice(i, 1);
  						break;
  					}
  				}
  				return hostsobject;
  			}
  		});
  	}
docs: 将一条host从一个组移动到另一个组