IntervalClause { private ExprValue month(ExprValue value) { return new ExprIntervalValue(Period.ofMonths(getIntegerValue(value))); }  void register(BuiltinFunctionRepository repository);  }
@Test public void month() { FunctionExpression expr = dsl.interval(DSL.literal(1), DSL.literal("month")); assertEquals(INTERVAL, expr.type()); assertEquals(intervalValue(Period.ofMonths(1)), expr.valueOf(env)); }