#vulnerable code 
                                @Test
    public void testCSVCommonsUpsert_WithTimestamp() throws Exception {
        CSVParser parser = null;
        PhoenixConnection conn = null;
        try {

            // Create table
            String statements = "CREATE TABLE IF NOT EXISTS TS_TABLE "
                    + "(ID BIGINT NOT NULL PRIMARY KEY, TS TIMESTAMP);";
            conn = DriverManager.getConnection(getUrl()).unwrap(
                    PhoenixConnection.class);
            PhoenixRuntime.executeStatements(conn,
                    new StringReader(statements), null);

            // Upsert CSV file
            CSVCommonsLoader csvUtil = new CSVCommonsLoader(conn, "TS_TABLE",
                    null, true, ',', '"', null, "!");
            csvUtil.upsert(
                    new StringReader("ID,TS\n"
                            + "1,1970-01-01 00:00:10\n"
                            + "2,1970-01-01 00:00:10.123\n"));

            // Compare Phoenix ResultSet with CSV file content
            PreparedStatement statement = conn
                    .prepareStatement("SELECT ID, TS FROM TS_TABLE ORDER BY ID");
            ResultSet phoenixResultSet = statement.executeQuery();
            assertTrue(phoenixResultSet.next());
            assertEquals(1L, phoenixResultSet.getLong(1));
            assertEquals(10000L, phoenixResultSet.getTimestamp(2).getTime());
            assertTrue(phoenixResultSet.next());
            assertEquals(2L, phoenixResultSet.getLong(1));
            assertEquals(10123L, phoenixResultSet.getTimestamp(2).getTime());
            assertFalse(phoenixResultSet.next());
        } finally {
            if (parser != null)
                parser.close();
            if (conn != null)
                conn.close();
        }
    } 
                            #location 18 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Test
    public void testCSVCommonsUpsert_WithTimestamp() throws Exception {
        CSVParser parser = null;
        PhoenixConnection conn = null;
        try {

            // Create table
            String statements = "CREATE TABLE IF NOT EXISTS TS_TABLE "
                    + "(ID BIGINT NOT NULL PRIMARY KEY, TS TIMESTAMP);";
            conn = DriverManager.getConnection(getUrl()).unwrap(
                    PhoenixConnection.class);
            PhoenixRuntime.executeStatements(conn,
                    new StringReader(statements), null);

            // Upsert CSV file
            CSVCommonsLoader csvUtil = new CSVCommonsLoader(conn, "TS_TABLE",
                    ImmutableList.<String>of(), true, ',', '"', null, "!");
            csvUtil.upsert(
                    new StringReader("ID,TS\n"
                            + "1,1970-01-01 00:00:10\n"
                            + "2,1970-01-01 00:00:10.123\n"));

            // Compare Phoenix ResultSet with CSV file content
            PreparedStatement statement = conn
                    .prepareStatement("SELECT ID, TS FROM TS_TABLE ORDER BY ID");
            ResultSet phoenixResultSet = statement.executeQuery();
            assertTrue(phoenixResultSet.next());
            assertEquals(1L, phoenixResultSet.getLong(1));
            assertEquals(10000L, phoenixResultSet.getTimestamp(2).getTime());
            assertTrue(phoenixResultSet.next());
            assertEquals(2L, phoenixResultSet.getLong(1));
            assertEquals(10123L, phoenixResultSet.getTimestamp(2).getTime());
            assertFalse(phoenixResultSet.next());
        } finally {
            if (parser != null)
                parser.close();
            if (conn != null)
                conn.close();
        }
    }