output: #fixed code
                                @Test
    public void testGarbageCollectorExports() {
      assertEquals(
          100L,
          registry.getSampleValue(
              "jvm_gc_collection_seconds_count",
              new String[]{"gc"},
              new String[]{"MyGC1"}),
          .0000001);
      assertEquals(
          10d,
          registry.getSampleValue(
              "jvm_gc_collection_seconds_sum",
              new String[]{"gc"},
              new String[]{"MyGC1"}),
          .0000001);
      assertEquals(
          200L,
          registry.getSampleValue(
              "jvm_gc_collection_seconds_count",
              new String[]{"gc"},
              new String[]{"MyGC2"}),
          .0000001);
      assertEquals(
          20d,
          registry.getSampleValue(
              "jvm_gc_collection_seconds_sum",
              new String[]{"gc"},
              new String[]{"MyGC2"}),
          .0000001);
    }
input: #vulnerable code 
                                @Test
    public void testGarbageCollectorExports() {
      assertEquals(
          100L,
          registry.getSampleValue(
              GarbageCollectorExports.COLLECTIONS_COUNT_METRIC,
              new String[]{"gc"},
              new String[]{"MyGC1"}),
          .0000001);
      assertEquals(
          10d,
          registry.getSampleValue(
              GarbageCollectorExports.COLLECTIONS_TIME_METRIC,
              new String[]{"gc"},
              new String[]{"MyGC1"}),
          .0000001);
      assertEquals(
          200L,
          registry.getSampleValue(
              GarbageCollectorExports.COLLECTIONS_COUNT_METRIC,
              new String[]{"gc"},
              new String[]{"MyGC2"}),
          .0000001);
      assertEquals(
          20d,
          registry.getSampleValue(
              GarbageCollectorExports.COLLECTIONS_TIME_METRIC,
              new String[]{"gc"},
              new String[]{"MyGC2"}),
          .0000001);
    } 
                              #location 5 
                              #vulnerability type NULL_DEREFERENCE