code: public boolean matchesSystemAndValue(BaseIdentifierDt theIdentifier) {
  		if (theIdentifier == null) {
  			return false;
  		}
  		return getValueElement().equals(theIdentifier.getValueElement()) && getSystemElement().equals(theIdentifier.getSystemElement());
  	}
docs: Returns true if <code>this</code> identifier has the same {@link #getValueElement() value} and
  {@link #getSystemElement() system} (as compared by simple equals comparison). Does not compare other values (e.g.
  getUse()) or any extensions.