code: public String sign(BoxSignatureAlgorithm algorithm, String key, String webHookPayload, String deliveryTimestamp) {
          return Base64.encode(this.signRaw(algorithm, key, webHookPayload, deliveryTimestamp));
      }
docs: Calculates signature for a provided information.
  
  @param algorithm
  for which algorithm
  @param key
  used by signing
  @param webHookPayload
  for singing
  @param deliveryTimestamp
  for signing
  @return calculated signature