code: final String removeUnit(String value)
  	{
  		final int i;
  		if (dpt.getUnit().length() > 0 && (i = value.lastIndexOf(dpt.getUnit())) > -1)
  			return value.substring(0, i).trim();
  		// java number parsing routines are really picky, remove WS
  		return value.trim();
  	}
docs: Returns value with unit cut off at end of string, if current DPT has a unit
  specified.
  <p>
  Whitespace are removed from both ends.
  
  @param value value string representation
  @return trimmed value string without unit