code: private final String load(String key, String defaultValue, String comment) {
      	if(options.containsKey(key)) {
      		return options.get(key);
      	} else if (config.getProperty(key) != null) {
              return config.getString(key);
          } else {
              if (defaultValue != null) {
                  try {
                      config.addProperty(key, defaultValue);
                      if (comment != null) {
                          propertiesConfigurationLayout.setComment(key, comment);
                      } else {
                          propertiesConfigurationLayout
                                  .setComment(
                                          key,
                                          "Automatically added default value. Please see Client Properties documentation on ExtWebDriver homepage.");
                      }
                      config.save(config.getPath());
                  } catch (ConfigurationException e) {
                      logger.error("Error saving updated property file ('" + config.getPath() + "')"
                              + e);
                  }
              }
              return defaultValue;
          }
      }
docs: Loads the given key/value pair into the configuration.
  <p>
  If the configuration already contains the given key, no change is made to
  the configuration.
  
  @param key
  the key to be put into the configuration
  @param defaultValue
  the value to be put into the configuration; if {@code null},
  then no change is made to the configuration
  @param comment
  a comment to be set for the key/value pair; {@code null}
  values permitted
  @return the newly set value, or the current value if the configuration
  already contains the given key