### Question:
DocbookUtils { public static char trademarkFromClass( final String trade ) { if ( "registered".equals( trade ) ) { return '\u00AE'; } else if ( "copyright".equals( trade ) ) { return '\u00A9'; } else if ( "service".equals( trade ) ) { return '\u2120'; } else if ( "trade".equals( trade ) ) { return '\u2122'; } else { throw new IllegalArgumentException( "Not a trademark class: " + trade ); } } private  DocbookUtils(); static String doxiaTableFrameAttribute( final String frame ); static int doxiaListNumbering( final String style ); static String docbookListNumbering( final int numbering ); static char trademarkFromClass( final String trade );  }### Answer:
@Test public void testTrademarkFromClass() { assertEquals( '\u00AE', DocbookUtils.trademarkFromClass( "registered" ) ); assertEquals( '\u00A9', DocbookUtils.trademarkFromClass( "copyright" ) ); assertEquals( '\u2120', DocbookUtils.trademarkFromClass( "service" ) ); assertEquals( '\u2122', DocbookUtils.trademarkFromClass( "trade" ) ); try { DocbookUtils.trademarkFromClass( "" ); fail(); } catch ( IllegalArgumentException e ) { assertNotNull( e ); } }