code: function cleanCallback(errorCallback, callback){
    var self = this || {};
    if(!callback){
      return function(err){ // remove other variables
        if(err && self.log){
          self.log('error',err);
        }
        errorCallback(err);
      }
    }
    
    return function(err){
      if(err){
        if(self.log){
          self.log('error',err);
        }
        errorCallback(err);
        return;
      }
      callback.apply(callback, Array.prototype.slice.call(arguments,1));
    }
  }
docs: Function for wraping callback to handle errors
  
  @param {Function} errorCallback callback used upon error
  @param {Function} [callback] callback used when no error