code: @Nullable
    public static BigDecimal parseBigDecimal (@Nullable final String sStr,
                                              @Nonnegative final int nScale,
                                              @Nonnull final RoundingMode eRoundingMode)
    {
      return parseBigDecimal (sStr, nScale, eRoundingMode, null);
    }
docs: Parse the given {@link String} as {@link BigDecimal}.
  
  @param sStr
  The String to parse. May be <code>null</code>.
  @param nScale
  The scaling (decimal places) to be used for the result. Must be &ge;
  0!
  @param eRoundingMode
  The rounding mode to be used to achieve the scale. May not be
  <code>null</code>.
  @return <code>null</code> if the string does not represent a valid value.