public String getSourceType() {
        return this.sourceType;
    }
<p>
The type of source that is generating the events. For example, if you want to be notified of events generated by
a DB instance, you would set this parameter to db-instance. For RDS Proxy events, specify <code>db-proxy</code>.
If this value isn't specified, all events are returned.
</p>
<p>
Valid Values:
<code> db-instance | db-cluster | db-parameter-group | db-security-group | db-snapshot | db-cluster-snapshot | db-proxy | zero-etl | custom-engine-version | blue-green-deployment </code>
</p>

@return The type of source that is generating the events. For example, if you want to be notified of events
        generated by a DB instance, you would set this parameter to db-instance. For RDS Proxy events, specify
        <code>db-proxy</code>. If this value isn't specified, all events are returned.</p>
        <p>
        Valid Values:
        <code> db-instance | db-cluster | db-parameter-group | db-security-group | db-snapshot | db-cluster-snapshot | db-proxy | zero-etl | custom-engine-version | blue-green-deployment </code>
aws-java-sdk-rds/src/main/java/com/amazonaws/services/rds/model/ModifyEventSubscriptionRequest.java