 rounding
      is necessary, the current
      <a href='#rounding-mode'><code>ROUNDING_MODE</code></a> is used.
    </p>
    <p>
      If the value of this BigNumber in exponential notation has fewer fraction
      digits then is specified by <code>decimal_places</code>, the return value
      will be appended with zeros accordingly.
    </p>
    <p>
      If <code>decimal_places</code> is omitted, or is <code>null</code> or
      undefined, the number of digits after the decimal point defaults to the
    