public String getFilter() {
        return this.filter;
    }
<p>
An expression that looks like a SQL WHERE clause that must return a Boolean value. Messages that satisfy the
condition are passed to the next activity.
</p>

@return An expression that looks like a SQL WHERE clause that must return a Boolean value. Messages that satisfy
        the condition are passed to the next activity.
aws-java-sdk-iotanalytics/src/main/java/com/amazonaws/services/iotanalytics/model/FilterActivity.java