#vulnerable code 
                                public Collection<String> links(final String pid, final String rel)
        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 Xocument(item).xpath(
                String.format(
                    "/catalog/project[@id='%s']/links/link[@rel='%s']/@href",
                    pid, rel
                )
            );
        }
    } 
                            #location 7 
                            #vulnerability type RESOURCE_LEAK
#fixed code
                                public Collection<String> links(final String pid, final String rel)
        throws IOException {
        this.checkExist(pid);
        try (final Item item = this.item()) {
            return new Xocument(item).xpath(
                String.format(
                    "/catalog/project[@id='%s']/links/link[@rel='%s']/@href",
                    pid, rel
                )
            );
        }
    }