docs: function(uid, sid, group) {
    if(!uid || !sid || !group) {
      return false;
    }
  
    for(let i=0, l=group.length; i<l; i++) {
      if(group[i] === uid) {
        group.splice(i, 1);
        return true;
      }
    }
  
    return false;
  }