@param $key

@return Schema|null
548033
protected function getSchemaForKey ($key) {
		if ($this -> schema) {
			if ($this -> schema -> has($key)) {
				$schema = $this -> schema -> get($key);
				return $schema instanceof Schema ? $schema : null;
			}
		}

		return null;
	}
1041761
public function load($key)
    {
        if (file_exists($path = $this->path . $key)) {
            return unserialize(file_get_contents($path));
        }

        return null;
    }
460279
private function getField($key)
    {
        return isset($this->data[$key]) ? $this->data[$key] : null;
    }
804423
public function getQueryParameter($key)
    {
        $queryStringArray = $this->getQueryStringAsArray();

        if (array_key_exists($key, $queryStringArray)) {
            return $queryStringArray[$key];
        }

        return null;
    }
722738
private function getSchemaCache($key)
    {
        if (isset($this->model_schema_cache[$key])) {
            return $this->model_schema_cache[$key];
        }

        return false;
    }
388543
private static function getSchema($parameter, $key)
    {
        if (is_object($parameter)) {
            // list validation
            return $parameter;
        } elseif (is_array($parameter) && array_key_exists($key, $parameter)) {
            // tuple validation
            return $parameter[$key];
        }

        return null;
    }
605360
private function getFromCacheByKey($key)
    {
        if ( ! $this->cache->contains($key)) {
            return null;
        }

        $serialized = $this->cache->fetch($key);

        return $this->unserializeAcl($serialized);
    }
259878
protected function result(Schema $schema)
    {
        $key = $this->generateVisitKey($schema);
        if (array_key_exists($key, $this->results)) {
            return $this->results[$key];
        }

        return null;
    }
236017
public function getParameter($key)
    {
        return isset($this->params[$key]) ? $this->params[$key] : null;
    }
535971
private function getCache($key)
    {
        $cache = $this->client->getItem($key);
        if ($cache->isHit()) {
            return $cache->get();
        }

        return null;
    }
1306511
public function schema($schema = null)
    {
        if (func_num_args() === 0) {
            return $this->collection->schema();
        }

        return $this->collection->schema($schema);
    }
946467
public function getPropertyMetadata($key)
    {
        if (array_key_exists($key, $this->entityPropertiesMetadata)) {
            return $this->entityPropertiesMetadata[$key];
        }

        return null;
    }
39216
public function getParameter($key)
    {
        $query = $this->getQuery();

        return isset($query[$key]) ? $query[$key] : null;
    }
630735
protected function getScript($key)
    {
        if (!isset($this->blueprintConfig[$key])) {
            return null;
        }
        $script = is_array($this->blueprintConfig[$key]) ? implode("\n", $this->blueprintConfig[$key]) : $this->blueprintConfig[$key];

        return $this->valueResolver->resolvePlaceholders($script, $this, 'script');
    }
339555
protected function getProperty($key)
    {
        return isset($this->properties[$key]) ? $this->properties[$key] : null;
    }
73674
protected function localKey($key)
    {
        if (empty($this->schema[$key])) {
            return null;
        }

        return $this->getAlias() . '.' . $this->schema[$key];
    }
650115
public function retrieve(string $key)
    {
        $token = null;

        $storageInstance = $this->getRepository();

        $token = $storageInstance->{$key}?? null;

        return $token;
    }