code: public static double toDouble(@Nullable final String doubleStr, final double defaultDouble) {
          return StringUtils.isNoneEmpty(doubleStr) ? toDouble(doubleStr) : defaultDouble;
      }
docs: If the double string is null or empty, it returns the defaultDouble otherwise it returns the duoble value (see toDouble)
  
  @param doubleStr     the double to convert
  @param defaultDouble the default value if the doubleStr is null or the empty string
  @return the double value of the string or the defaultDouble is the double string is empty
  @throws IllegalArgumentException if the passed double string is not a valid double