public ApiCallDetails withFirstSeen(java.util.Date firstSeen) {
        setFirstSeen(firstSeen);
        return this;
    }
<p>
The first date and time, in UTC and extended ISO 8601 format, when any operation was invoked and produced the
finding.
</p>

@param firstSeen
       The first date and time, in UTC and extended ISO 8601 format, when any operation was invoked and produced
       the finding.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-macie2/src/main/java/com/amazonaws/services/macie2/model/ApiCallDetails.java