question: public void updateTopic ( String topic , DbContextRule rule ) { topic = StringUtils . toLowerEnglish ( topic ) ; RuleHead head = ruleMap . get ( topic ) ; if ( head == null ) { head = new RuleHead ( "db" , topic , rule ) ; ruleMap . put ( topic , head ) ; statements . add ( head ) ; } else { head . setRule ( rule ) ; } }
target:  Update a topic with a context specific rule. This is used for autocomplete support.