@param string $key

@return string|null
14040
public function getAdditionalHeader(string $key)
    {
        if (! $this->hasAdditionalHeader($key)) {
            return null;
        }

        return $this->additionalHeaders[$key];
    }
1126558
public function get($key)
	{
		$key = strtolower($key);
		if (isset($this->summoners[$key]))
		{
			return $this->summoners[$key];
		}

		return null;
	}
838674
public function getQueryParam($key)
    {
        if (isset($this->queryParams[$key])) {
            return $this->queryParams[$key];
        }
        return null;
    }
1048715
public function get($key){
		return (isset($this->tpl['vars'][$key])) ? $this->tpl['vars'][$key] : null;
	}
1065938
public function getHeaderValue($key)
    {
        return isset($this->headers[$key]) ? $this->headers[$key] : null;
    }
324833
public function get($key)
    {
        if (!$this->isEnabled()) {
            return null;
        }

        $value = $this->server->get($this->prefix . $key);

        return false === $value ? null : $value;
    }
804423
public function getQueryParameter($key)
    {
        $queryStringArray = $this->getQueryStringAsArray();

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

        return null;
    }
748056
public function getHeader($key)
	{
		$key = strtolower($key);

		return isset($this->headers[$key]) ? $this->headers[$key] : null;
	}
126849
protected function getUrlForKey($key)
    {
        return isset($this->urls[$key]) ? $this->urls[$key] : null;
    }
376063
public function offsetGet( $key )
    {
        $key = strtolower( $key );
        if ( !array_key_exists( $key, $this->lookup ) )
        {
            return null;
        }
        return $this->map[$this->lookup[$key]];
    }
149279
public function getParamValue($key)
    {
        $value = null;
        if (is_array($param = $this->getParam($key))) {
            $value = $param['value'];
        }

        return $value;
    }
136170
public static function get(string $key)
    {
        $encodedValue = @file_get_contents(self::determineDabaseFilePathFor($key));
        if ($encodedValue === false) {
            return null;
        }

        return Json::decode($encodedValue);
    }
969519
public function get($key)
	{
		if ( ! isset($this->strings[$key]))
		{
			return null;
		}

		return $this->strings[$key];
	}
534405
public function header( string$key=null )
	{
		return ( isset($key) ?
			$this->headers[ucwords( strtolower($key), '-' )]
			:
			$this->getHeaders()
		);
	}
665904
public function get($key = null)
    {
        if (null === $key) {
            return $this->get;
        }

        return isset($this->get[$key]) ? $this->get[$key] : null;
    }
1334829
public function offsetGet($key) {
		$key = strtolower($key);
		return isset($this->data[$key]) ? $this->data[$key] : null;
	}
139158
protected function get($key)
    {
        return isset($this->errors[$key]) ? $this->errors[$key] : null;
    }