code: private boolean canOpen(String resourceLocation) {
          if (resourceLocation == null) {
              throw new InvalidArgument("resourceLocation", resourceLocation);
          }
  
          synchronized (resourceLocation) {
              // find the resource in the cache
              CachedResource cachedResource = cacheLookupService
                      .findInCache(NAMESPACES, resourceLocation);
  
              if (cachedResource == null) {
                  return false;
              }
  
              String indexPath = asPath(
                      cachedResource.getLocalFile().getAbsolutePath(),
                      NS_INDEX_FILE_NAME);
  
              JDBMNamespaceLookup il = new JDBMNamespaceLookup(indexPath);
              try {
                  il.open();
                  il.close();
              } catch (IOException e) {
                  return false;
              }
  
              return true;
          }
      }
docs: Determines if the {@link Namespace} resource location can be opened for
  lookups. To be opened
  
  @param resourceLocation
  @return