#vulnerable code 
                                public Collection<String> links(final String pid) throws IOException {
        if (!this.exists(pid)) {
            throw new IllegalArgumentException(
                new Par(
                    "Project %s doesn't exist, can't get links"
                ).say(pid)
            );
        }
        try (final Item item = this.item()) {
            return new SolidList<>(
                new Mapped<>(
                    xml -> String.format(
                        "%s:%s",
                        xml.xpath("@rel").get(0),
                        xml.xpath("@href").get(0)
                    ),
                    new Xocument(item).nodes(
                        String.format(
                            "/catalog/project[@id='%s']/links/link",
                            pid
                        )
                    )
                )
            );
        }
    } 
                            #location 6 
                            #vulnerability type RESOURCE_LEAK
#fixed code
                                public Collection<String> links(final String pid) throws IOException {
        this.checkExist(pid);
        try (final Item item = this.item()) {
            return new SolidList<>(
                new Mapped<>(
                    xml -> String.format(
                        "%s:%s",
                        xml.xpath("@rel").get(0),
                        xml.xpath("@href").get(0)
                    ),
                    new Xocument(item).nodes(
                        String.format(
                            "/catalog/project[@id='%s']/links/link",
                            pid
                        )
                    )
                )
            );
        }
    }