code: public void write(LicenseKeyPair pair, IOFormat format) throws IOException {
          switch (format) {
              case BINARY:
                  osPrivate.write(pair.getPrivate());
                  osPublic.write(pair.getPublic());
                  return;
              case BASE64:
                  osPrivate.write(Base64.getEncoder().encode(pair.getPrivate()));
                  osPublic.write(Base64.getEncoder().encode(pair.getPublic()));
                  return;
          }
          throw new IllegalArgumentException("Key format " + format + " is unknown.");
      }
docs: Write the key pair into the output files.
  
  @param pair the key pair to write.
  @param format that can be {@link IOFormat#BINARY} or {@link IOFormat#BASE64}. Using {@link IOFormat#STRING}
  will throw exception as keys, as opposed to licenses, cannot be saved in string format.
  @throws IOException when the underlying media cannot be written