public function keyExists($key)
    {
        $allKeys = $this->getKeys();
        if (array_key_exists($key, $allKeys)) {
            return true;
        }
        return false;
    }
public function keyExists($key)
    {
        $allKeys = $this->getKeys();
        if (array_key_exists($key, $allKeys)) {
            return true;
        }
        return false;
    }
public function keyExists ( $ key ) { $ allKeys = $ this -> getKeys ( ) ; if ( array_key_exists ( $ key , $ allKeys ) ) { return true ; } return false ; }
Check, if a given key is exists in the file content

@param  string  $keys

@return bool
Check if a given key is exists in the file content