protected void setValueFromString(String newValue) {
    if (newValue == null) {
      throw new IllegalArgumentException(
          String.format("Unable to set %s to null value",
              getName()));
    }

    if (isInetAddress()) {
      value = toInetAddress(newValue);
    } else if (isFile()) {
      value = new File(newValue);
    } else if (isOctal()) {
      if (!newValue.startsWith("0")) {
        newValue = "0" + newValue;
      }
      value = Integer.parseInt(newValue, 8);
    } else if (isArray()) {
      // parse it TODO
      throw new IllegalArgumentException(
          "Setting array value from delimited string is not supported");
    } else {
      value = newValue;
    }
  }
Removes the listener if it's currently registered.
geode-core/src/main/java/org/apache/geode/admin/internal/ConfigurationParameterImpl.java