question: protected void handleSpecialSubstitution ( String replace , String replaceWith , int startPos , String description ) { super . handleSpecialSubstitution ( replace , replaceWith , startPos , description ) ; if ( replace . equals ( "<dictionary>" ) ) { if ( replaceWith . charAt ( 0 ) == '(' ) { error ( "Dictionary group can't be enclosed in (" , startPos , description ) ; } dictionaryExpression = replaceWith ; dictionaryChars = CharSet . parseString ( replaceWith ) ; } }
target:  We override handleSpecialSubstitution() to add logic to handle the <dictionary> tag.  If we see a substitution named "<dictionary>", parse the substitution expression and store the result in dictionaryChars.