public function remove_counter($key, $super_column, $column=null,
                                   $consistency_level=null) {
        $cp = new ColumnPath();
        $packed_key = $this->pack_key($key);
        $cp->column_family = $this->column_family;
        $cp->super_column = $this->pack_name($super_column, true);
        if ($column !== null)
            $cp->column = $this->pack_name($column);
        $this->pool->call("remove_counter", $packed_key, $cp,
            $this->wcl($consistency_level));
    }