public java.util.List<SourceDetail> getSourceDetails() {
        if (sourceDetails == null) {
            sourceDetails = new com.amazonaws.internal.SdkInternalList<SourceDetail>();
        }
        return sourceDetails;
    }
<p>
Provides the source and the message types that cause Config to evaluate your Amazon Web Services resources
against a rule. It also provides the frequency with which you want Config to run evaluations for the rule if the
trigger type is periodic.
</p>
<p>
If the owner is set to <code>CUSTOM_POLICY</code>, the only acceptable values for the Config rule trigger message
type are <code>ConfigurationItemChangeNotification</code> and
<code>OversizedConfigurationItemChangeNotification</code>.
</p>

@return Provides the source and the message types that cause Config to evaluate your Amazon Web Services
        resources against a rule. It also provides the frequency with which you want Config to run evaluations
        for the rule if the trigger type is periodic.</p>
        <p>
        If the owner is set to <code>CUSTOM_POLICY</code>, the only acceptable values for the Config rule trigger
        message type are <code>ConfigurationItemChangeNotification</code> and
        <code>OversizedConfigurationItemChangeNotification</code>.
aws-java-sdk-config/src/main/java/com/amazonaws/services/config/model/Source.java