question: protected void handleSpecialSubstitution ( String replace , String replaceWith , int startPos , String description ) { if ( replace . equals ( "<ignore>" ) ) { if ( replaceWith . charAt ( 0 ) == '(' ) { error ( "Ignore group can't be enclosed in (" , startPos , description ) ; } ignoreChars = CharSet . parseString ( replaceWith ) ; } }
target:  This function defines a protocol for handling substitution names that are "special," i.e., that have some property beyond just being substitutions.  At the RuleBasedBreakIterator level, we have one special substitution name, "<ignore>".  Subclasses can override this function to add more.  Any special processing that has to go on beyond that which is done by the normal substitution-processing code is done here.