docs: public RestletUtilUser findUser(final String userIdentifier)
      {
          if(userIdentifier == null)
          {
              throw new NullPointerException("User identifier was null");
          }
          
          RestletUtilUser result = null;
          
          RepositoryConnection conn = null;
          try
          {
              conn = this.repository.getConnection();
              
              final String query = this.buildSparqlQueryToFindUser(userIdentifier, false);
              
              this.log.debug("findUser: query={}", query);
              
              final TupleQuery tupleQuery = conn.prepareTupleQuery(QueryLanguage.SPARQL, query);
              
              final TupleQueryResult queryResult = tupleQuery.evaluate();
              
              try
              {
                  if(queryResult.hasNext())
                  {
                      final BindingSet bindingSet = queryResult.next();
                      
                      result = this.buildRestletUserFromSparqlResult(userIdentifier, bindingSet);
                  }
                  else
                  {
                      this.log.info("Could not find user with identifier, returning null: {}", userIdentifier);
                  }
              }
              finally
              {
                  queryResult.close();
              }
              
          }
          catch(final RepositoryException e)
          {
              throw new RuntimeException("Failure finding user in repository", e);
          }
          catch(final MalformedQueryException e)
          {
              throw new RuntimeException("Failure finding user in repository", e);
          }
          catch(final QueryEvaluationException e)
          {
              throw new RuntimeException("Failure finding user in repository", e);
          }
          finally
          {
              try
              {
                  conn.close();
              }
              catch(final RepositoryException e)
              {
                  this.log.error("Failure to close connection", e);
              }
          }
          
          return result;
      }