func (api AmazonProductAPI) ItemLookupWithParams(params map[string]string) (string, error) {
	_, present := params["ItemId"]
	if !present {
		return "", errors.New("ItemId property is required in the params map")
	}
	return api.genSignAndFetch("ItemLookup", params)
}
/*
ItemLookupWithParams takes the params for ItemLookup and returns the result
package amazonproduct
import (
	"errors"
	"fmt"
	"strconv"
	"strings"
)
func (api AmazonProductAPI) ItemLookup(ItemId string) (string, error) {
	params := map[string]string{
		"ItemId":        ItemId,
		"ResponseGroup": "Images,ItemAttributes,Small,EditorialReview",
	}
	return api.genSignAndFetch("ItemLookup", params)
}
func (api AmazonProductAPI) ItemLookupWithResponseGroup(ItemId string, ResponseGroup string) (string, error) {
	params := map[string]string{
		"ItemId":        ItemId,
		"ResponseGroup": ResponseGroup,
	}
	return api.genSignAndFetch("ItemLookup", params)
}