src/Common/Factory/HttpRequest.php
public function getHeader($sHeader)
    {
        return isset($this->aHeaders[$sHeader]) ? $this->aHeaders[$sHeader] : null;
    }
public function getHeader($sHeader)
    {
        return isset($this->aHeaders[$sHeader]) ? $this->aHeaders[$sHeader] : null;
    }
public function getHeader ( $ sHeader ) { return isset ( $ this -> aHeaders [ $ sHeader ] ) ? $ this -> aHeaders [ $ sHeader ] : null ; }
Returns a single header

@param string $sHeader The header to return

@return mixed|null
Returns a single header