code: public boolean getBoolean(String property) {
      return getProperty(property, value -> {
        switch (value.trim().toLowerCase()) {
          case "true":
          case "1":
            return true;
          case "false":
          case "0":
            return false;
          default:
            throw new ConfigurationException("invalid property value: " + property + " must be a boolean");
        }
      });
    }
docs: Reads a boolean property.
  
  @param property The property name.
  @return The property value.
  @throws ConfigurationException if the property is not present