code: public static String getStringOptional(
      final Properties properties,
      final String key,
      final String other)
    {
      Objects.requireNonNull(properties, "Properties");
      Objects.requireNonNull(key, "Key");
      Objects.requireNonNull(other, "Default value");
  
      final String value = properties.getProperty(key);
      if (value == null) {
        return other;
      }
      return value;
    }
docs: <p> Returns the string value associated with {@code key} in the
  properties referenced by {@code props} if it exists, otherwise returns
  {@code other}. </p>
  
  @param other      The default value
  @param properties The loaded properties.
  @param key        The requested key.
  
  @return The value associated with the given key