final Set<String> keys2 = context.getContextKeys() ;
assertNotNull("Context keys2", keys2) ;
assertEquals("Context key count", 1, keys2.size()) ;
assertTrue("Contains key", keys2.contains("foo")) ;
context.clearContext() ;
final Set<String> keys3 = context.getContextKeys() ;
assertNotNull("Context keys3", keys3) ;
assertEquals("Context key count", 0, keys3.size()) ;