### Question:
FoConfiguration { public String getAttributeString( String attributeId ) { if ( attributeId == null ) { return ""; } reset(); addAttributes( attributeId ); return SinkUtils.getAttributeString( attributeSet ); } FoConfiguration(); void load( File configFile ); String getAttributeString( String attributeId ); MutableAttributeSet getAttributeSet( String attributeId );  }### Answer:
@Test public void testGetAttributeString() { FoConfiguration config = new FoConfiguration(); assertEquals( "Null attribute ID should return empty string!", "", config.getAttributeString( null ) ); assertEquals( "Non existent attribute ID should return empty string!", "", config.getAttributeString( "a.dummy.attribute" ) ); assertEquals( "Wrong attributes returned for italic!", " font-style=\"italic\"", config.getAttributeString( "italic" ) ); }