public void setUserNamesToAdd(java.util.Collection<String> userNamesToAdd) {
        if (userNamesToAdd == null) {
            this.userNamesToAdd = null;
            return;
        }

        this.userNamesToAdd = new java.util.ArrayList<String>(userNamesToAdd);
    }
<p>
A list of users being added to the ACL
</p>

@param userNamesToAdd
       A list of users being added to the ACL
aws-java-sdk-memorydb/src/main/java/com/amazonaws/services/memorydb/model/ACLPendingChanges.java