code: @Override
      public boolean exists(final FedoraSession session, final String path) {
          final Session jcrSession = getJcrSession(session);
          try {
              validatePath(jcrSession, path);
              return jcrSession.nodeExists(path);
          } catch (final IllegalArgumentException e) {
              throw new InvalidResourceIdentifierException("Illegal path: " + path);
          } catch (final RepositoryException e) {
              throw new RepositoryRuntimeException(e);
          }
      }
docs: /* (non-Javadoc)
  @see org.fcrepo.kernel.api.services.Service#exists(javax.jcr.Session, java.lang.String)