def trim!
      # check if trimming is needed
      if (self.trim_max_length > 0) && (self.count > self.trim_max_length)
        last_tle = self.find(1, :skip => self.trim_max_length - 1).first
        if last_tle
          self.delete(:before => last_tle.activity.at)
        end
      end
    end
def trim!
      # check if trimming is needed
      if (self.trim_max_length > 0) && (self.count > self.trim_max_length)
        last_tle = self.find(1, :skip => self.trim_max_length - 1).first
        if last_tle
          self.delete(:before => last_tle.activity.at)
        end
      end
    end
Remove old timeline entries