public void setPrincipalId(String principalId) {
        this.principalId = principalId;
    }
<p>
The unique identifier for the IAM user who performed the action.
</p>

@param principalId
       The unique identifier for the IAM user who performed the action.
aws-java-sdk-macie2/src/main/java/com/amazonaws/services/macie2/model/IamUser.java