public Event withImpression(String... impression) {
        if (this.impression == null) {
            setImpression(new java.util.ArrayList<String>(impression.length));
        }
        for (String ele : impression) {
            this.impression.add(ele);
        }
        return this;
    }
<p>
A list of item IDs that represents the sequence of items you have shown the user. For example,
<code>["itemId1", "itemId2", "itemId3"]</code>. Provide a list of items to manually record impressions data for
an event. For more information on recording impressions data, see <a href=
"https://docs.aws.amazon.com/personalize/latest/dg/recording-events.html#putevents-including-impressions-data"
>Recording impressions data</a>.
</p>
<p>
<b>NOTE:</b> This method appends the values to the existing list (if any). Use
{@link #setImpression(java.util.Collection)} or {@link #withImpression(java.util.Collection)} if you want to
override the existing values.
</p>

@param impression
       A list of item IDs that represents the sequence of items you have shown the user. For example,
       <code>["itemId1", "itemId2", "itemId3"]</code>. Provide a list of items to manually record impressions
       data for an event. For more information on recording impressions data, see <a href=
       "https://docs.aws.amazon.com/personalize/latest/dg/recording-events.html#putevents-including-impressions-data"
       >Recording impressions data</a>.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-personalizeevents/src/main/java/com/amazonaws/services/personalizeevents/model/Event.java