#vulnerable code 
                                @Test
    public void testGetDefaultAnalyzer() {
        Map<String, Mapper> mappers = new HashMap<>();
        Schema schema = new Schema(new EnglishAnalyzer(), mappers, null);
        Analyzer analyzer = schema.getDefaultAnalyzer();
        assertEquals("Expected english analyzer", EnglishAnalyzer.class, analyzer.getClass());
        schema.close();
    } 
                            #location 6 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Test
    public void testGetDefaultAnalyzer() {
        Map<String, Mapper> mappers = new HashMap<>();
        Map<String, Analyzer> analyzers = new HashMap<>();
        Schema schema = new Schema(new EnglishAnalyzer(), mappers, analyzers);
        Analyzer analyzer = schema.getDefaultAnalyzer();
        assertEquals("Expected english analyzer", EnglishAnalyzer.class, analyzer.getClass());
        schema.close();
    }