public function getHeader(string $headerName)
	{
		return $this->hasHeader($headerName) ? $this->headers[ $headerName ] : null;
	}
public function getHeader(string $headerName)
	{
		return $this->hasHeader($headerName) ? $this->headers[ $headerName ] : null;
	}
public function getHeader ( string $ headerName ) { return $ this -> hasHeader ( $ headerName ) ? $ this -> headers [ $ headerName ] : null ; }
Get header from request

@param string $headerName

@return string|null
Get header from request