logback-android/src/main/java/ch/qos/logback/core/util/OptionHelper.java
static public String[] extractDefaultReplacement(String key) {
    String[] result = new String[2];
    if(key == null)
      return result;

    result[0] = key;
    int d = key.indexOf(DELIM_DEFAULT);
    if (d != -1) {
      result[0] = key.substring(0, d);
      result[1] = key.substring(d + DELIM_DEFAULT_LEN);
    }
    return result;
  }
static public String[] extractDefaultReplacement(String key) {
    String[] result = new String[2];
    if(key == null)
      return result;

    result[0] = key;
    int d = key.indexOf(DELIM_DEFAULT);
    if (d != -1) {
      result[0] = key.substring(0, d);
      result[1] = key.substring(d + DELIM_DEFAULT_LEN);
    }
    return result;
  }
Return a String[] of size two. The first item containing the key part and the second item
containing a default value specified by the user. The second item will be null if no default value
is specified.

@param key
@return array, where item 0 is the key, and item 1 is the default value