@param string $key

@return $this
973178
public function asTree($key = 'items')
    {
        $this->asArray(true);

        $this->treeKey = $key;

        return $this->order(['root', 'lft']);
    }
891896
public function releaseKey($key)
    {
        $this->executor->execute(DriverCommand::SEND_KEYS_TO_ACTIVE_ELEMENT, [
            'value' => [(string) $key],
        ]);

        return $this;
    }
889540
public function remove($key)
    {
        if ($this->has($key)) {
            $cont = clone $this;
            $cont->doRemove($key);

            return $cont;
        }

        return $this;
    }
480823
public function deleteItem($key)
    {
        $this->connect();

        $this->driver->delete($key);

        $rc = $this->driver->getResultCode();

        if (($rc != \Memcached::RES_SUCCESS)) {
            return $this;
        }

        return $this;
    }
298589
public function delete($key = null)
    {
        if ($key === null) {
            $this->reset();

            return $this;
        }

        $arr = &$this->getStackByReference($key);

        if (is_array($arr) && array_key_exists($key, $arr)) {
            unset($arr[$key]);
        }

        return $this;
    }
500410
public function resetFilter($key)
    {
        if (true === isset($this->filters[$key])) {
            unset($this->filters[$key]);
        }

        return $this;
    }
1164938
public function delete($key)
    {
        if (is_array($key)) {
            foreach ($key as $k) {
                $this->set($k, null);
            }
        } else {
            $this->set($key, null);
        }
        return $this;
    }
211439
public function key($key = null)
    {
        if (!func_num_args()) {
            return $this->_key;
        }
        $this->_key = $key;
        return $this;
    }
816290
public function unsetOption($key)
    {
        if (Core\Config::isValidOptionName($key) && isset($this->$key)) {
            unset($this->$key);
        }

        return $this;
    }
211717
public function removeKey($key)
    {
        if (is_array($key)) {
            foreach ($key as $k) {
                $this->removeKey($k);
            }

            return $this;
        }

        if ($this->keyExists($key)) {
            $array = $this->val();
            unset($array[$key]);

            $this->val($array);
        }

        return $this;
    }
851682
public function delete($key)
    {
        $this->pinba()->timerDelete($this->getTimer($key));
        $this->unsetTimer($key);

        return $this;
    }
718921
public function remove(string $key): self
    {
        if (isset($this->headers[$key]) == true) {
            unset($this->headers[$key]);
        }

        return $this;
    }
818598
public function delete($key)
    {
        $key = func_num_args() > 1 ? func_get_args() : $key;

        if (is_array($key)) {
            array_map([$this, __METHOD__], $key);

            return $this;
        }

        unset($this->options[$key]);

        return $this;
    }
995813
protected function _removeKey($key)
    {
        $keys = $this->get('__stored_keys__', []);
        if (in_array($key, $keys)) {
            $reverse = array_flip($keys);
            unset($reverse[$key]);
            $this->set('__stored_keys__', array_keys($reverse));
        }
        return $this;
    }
799893
public function set(string $key, $element): self
    {
        $this->validate($element);

        $this->elements[$key] = $element;

        foreach ($this->indexes as $index) {
            $index->add($key, $element);
        }

        return $this;
    }
1242734
public function forget($key)
    {
        unset($this->writeStorage[$key]);

        if ($this->bigStorage) {
            unset($this->bigStorage[$key]);
        }

        $this->entryCache[$key] = $this->createMissEntry();

        return $this;
    }
1229079
public function removeHeader($key)
    {
        if (isset($this->headers[$key])) {
            unset($this->headers[$key]);
        }
        return $this;
    }