public static <T> NullExpression<T> nullExpression(Class<T> type) {
        return new NullExpression<T>(type);
    }
Create a null expression for the specified type

@param type type of expression
@param <T> type of expression
@return null expression
querydsl-core/src/main/java/com/querydsl/core/types/dsl/Expressions.java