Don't call .size of .isEmpty in QueryVisitor.visit(TerminalClause) - it slows things down a lot

public QueryFactoryResult visit(final TerminalClause terminalClause)
    {
        if (rootClause)
        {
            return new QueryFactoryResult(createQuery(terminalClause));
        }
        final Collection<ClauseQueryFactory> clauseQueryFactory = this.queryRegistry.getClauseQueryFactory(queryCreationContext, terminalClause);

        if (clauseQueryFactory.isEmpty())
        {
            // This time we really mean it! When we are asked to run a query for things that no longer exist we will
            // run the query the best we can, adding false to the tree for bits that we can not resolve.
            return QueryFactoryResult.createFalseResult();
        }
        try
        {
            if (clauseQueryFactory.size() == 1)
            {
                ClauseQueryFactory factory = clauseQueryFactory.iterator().next();
                return factory.getQuery(queryCreationContext, terminalClause);
            }
            else
            {
                BooleanQuery query = new BooleanQuery();
                for (ClauseQueryFactory factory : clauseQueryFactory)
                {
                    query.add(makeQuery(factory.getQuery(queryCreationContext, terminalClause)), BooleanClause.Occur.SHOULD);
                }
                return new QueryFactoryResult(query);
            }
        }
        catch (BooleanQuery.TooManyClauses tooManyClauses)
        {
            throw new JqlTooComplex(terminalClause);
        }
        // This could happen for Factories that use their own QueryVisitors, e.g. SavedFilterCQF
        catch (JqlTooComplex jqlTooComplex)
        {
            throw new JqlTooComplex(terminalClause);
        }
    }

    public Collection<ClauseHandler> getClauseHandler(final User user, final String jqlClauseName)
    {
        return filter(getClauseHandler(jqlClauseName), new PermissionToUse(user));
    }