* @param string $ikm The input keying material
* @param string $salt The salt to add to the ikm, to get the prk
* @param string $info Optional context (change the output without affecting
- * the randomness properties of the output)
+ * the randomness properties of the output)
* @param int $L Number of bytes to return
* @return string Cryptographically secure pseudorandom binary string
*/