code: public void setPrecision(TemporalPrecisionEnum thePrecision) throws IllegalArgumentException {
  		if (thePrecision == null) {
  			throw new NullPointerException("Precision may not be null");
  		}
  		myPrecision = thePrecision;
  		updateStringValue();
  	}
docs: Sets the precision for this datatype using field values from {@link Calendar}. Valid values are:
  <ul>
  <li>{@link Calendar#SECOND}
  <li>{@link Calendar#DAY_OF_MONTH}
  <li>{@link Calendar#MONTH}
  <li>{@link Calendar#YEAR}
  </ul>
  
  @throws IllegalArgumentException