docs: function(in_thing){
  	var retval = false;
  	if( us.isArray(in_thing) ){
  	    if( in_thing.length == 0 ){
  		retval = true;
  	    }
  	}else if( _is_hash(in_thing) ){
  	    var in_hash_keys = us.keys(in_thing);
  	    if( in_hash_keys.length == 0 ){
  		retval = true;
  	    }
  	}else{
  	    // TODO: don't know about this case yet...
  	    //throw new Error('unsupported type in is_empty');	
  	    retval = false;
  	}
  	return retval;
      }