docs: private static void addSubsystemManifestRequireCapability(File esa,
                                                                Map<Path, String> requiresMap) throws IOException {
          String esaLocation = esa.getAbsolutePath();
          ZipFile zip = null;
          try {
              zip = new ZipFile(esaLocation);
              Enumeration<? extends ZipEntry> zipEntries = zip.entries();
              ZipEntry subsystemEntry = null;
              while (zipEntries.hasMoreElements()) {
                  ZipEntry nextEntry = zipEntries.nextElement();
                  if ("OSGI-INF/SUBSYSTEM.MF".equalsIgnoreCase(nextEntry.getName())) {
                      subsystemEntry = nextEntry;
                      break;
                  }
              }
              if (subsystemEntry == null) {
                  ;
              } else {
                  Manifest m = ManifestProcessor.parseManifest(zip.getInputStream(subsystemEntry));
                  Attributes manifestAttrs = m.getMainAttributes();
                  String requireCapabilityAttr = manifestAttrs.getValue(REQUIRE_CAPABILITY_HEADER_NAME);
                  requiresMap.put(esa.toPath(), requireCapabilityAttr);
              }
          } finally {
              if (zip != null) {
                  zip.close();
              }
          }
      }