Parse error: syntax error, unexpected 'public' (T_PUBLIC), expecting end of file in C:\xampp\htdocs\payuindia\payment_form_post.php on line 5

Question

I'm getting this error of : Parse error: syntax error, unexpected 'public' (T_PUBLIC), expecting end of file in C:\xampp\htdocs\payuindia\payment_form_post.php on line 5. Help me where I am getting wrong?

 public static function getHmacParameters($method, $path, $content, 
 $username, $salt) { 

 $version = "HTTP/1.1" ; 

 $requestLine = strtoupper($method) . " " . $path . " " . $version; 
 $dateString = gmdate('D, d M Y H:i:s T'); 
 $digest = base64_encode(hash("sha256", $content, true)); 

 $signing_headers = [ 
    'date' => $dateString, 
    'request-line' => $requestLine, 
    'digest' => $digest 
 ]; 

 $signing_string = ""; 
 $headers = ""; 
 foreach ($signing_headers as $key => $value) { 
    if ($key != "request-line") { 
        $signing_string .= $key . ":" . " "; 
    } 
    $signing_string .= $value . "\n"; 
    $headers .= $key . " "; 
 } 
 $signing_string = rtrim($signing_string, "\n"); 
 $headers = rtrim($headers, " "); 

 $hmacHash = hash_hmac("sha1", $signing_string, $salt, true); 

 $signature = base64_encode($hmacHash); 
 $authorization = "hmac username=\"$username\", algorithm=\"hmac-sha1\", 
 headers=\"$headers\", signature=\"$signature\""; 

 return [ 
    'dateString' => $dateString, 
    'digest' => $digest, 
    'authorization' => $authorization 
 ]; 

}