#vulnerable code 
                                @Test
    public void mergeNull() {
        PDDocument destination = new PDDocument();
        AcroFormsMerger victim = new AcroFormsMerger(AcroFormPolicy.MERGE, destination);
        assertNotNull(document.getDocumentCatalog().getAcroForm());
        victim.mergeForm(null, annotationsLookup);
        assertFalse(victim.hasForm());
        assertNull(destination.getDocumentCatalog().getAcroForm());
    } 
                            #location 8 
                            #vulnerability type RESOURCE_LEAK
#fixed code
                                @Test
    public void mergeNull() {
        PDDocument destination = new PDDocument();
        AcroFormsMerger victim = new AcroFormsMerger(AcroFormPolicy.MERGE, destination);
        assertNotNull(document.getDocumentCatalog().getAcroForm());
        victim.mergeForm(null, annotationsLookup);
        assertTrue(victim.getForm().getFields().isEmpty());
        assertNull(destination.getDocumentCatalog().getAcroForm());
    }