public String getDefaultSubstitutions() {
        return this.defaultSubstitutions;
    }
<p>
The JSON object that specifies the default values that are used for message variables in the message template.
This object is a set of key-value pairs. Each key defines a message variable in the template. The corresponding
value defines the default value for that variable.
</p>

@return The JSON object that specifies the default values that are used for message variables in the message
        template. This object is a set of key-value pairs. Each key defines a message variable in the template.
        The corresponding value defines the default value for that variable.
aws-java-sdk-pinpoint/src/main/java/com/amazonaws/services/pinpoint/model/PushNotificationTemplateResponse.java