public void setProperties(String properties) {
        this.properties = properties;
    }
<p>
A string map of event-specific data that you might choose to record. For example, if a user rates a movie on your
site, other than movie ID (<code>itemId</code>) and rating (<code>eventValue</code>) , you might also send the
number of movie ratings made by the user.
</p>
<p>
Each item in the map consists of a key-value pair. For example,
</p>
<p>
<code>{"numberOfRatings": "12"}</code>
</p>
<p>
The keys use camel case names that match the fields in the Item interactions dataset's schema. In the above
example, the <code>numberOfRatings</code> would match the 'NUMBER_OF_RATINGS' field defined in the Item
interactions dataset's schema.
</p>
<p>
The following can't be included as a keyword for properties (case insensitive).
</p>
<ul>
<li>
<p>
userId
</p>
</li>
<li>
<p>
sessionId
</p>
</li>
<li>
<p>
eventType
</p>
</li>
<li>
<p>
timestamp
</p>
</li>
<li>
<p>
recommendationId
</p>
</li>
<li>
<p>
impression
</p>
</li>
</ul>
<p>
This field's value must be valid JSON according to RFC 7159, including the opening and closing braces. For
example: '{"key": "value"}'.
</p>
<p>
The AWS SDK for Java performs a Base64 encoding on this field before sending this request to the AWS service.
Users of the SDK should not perform Base64 encoding on this field.
</p>

@param properties
       A string map of event-specific data that you might choose to record. For example, if a user rates a movie
       on your site, other than movie ID (<code>itemId</code>) and rating (<code>eventValue</code>) , you might
       also send the number of movie ratings made by the user.</p>
       <p>
       Each item in the map consists of a key-value pair. For example,
       </p>
       <p>
       <code>{"numberOfRatings": "12"}</code>
       </p>
       <p>
       The keys use camel case names that match the fields in the Item interactions dataset's schema. In the
       above example, the <code>numberOfRatings</code> would match the 'NUMBER_OF_RATINGS' field defined in the
       Item interactions dataset's schema.
       </p>
       <p>
       The following can't be included as a keyword for properties (case insensitive).
       </p>
       <ul>
       <li>
       <p>
       userId
       </p>
       </li>
       <li>
       <p>
       sessionId
       </p>
       </li>
       <li>
       <p>
       eventType
       </p>
       </li>
       <li>
       <p>
       timestamp
       </p>
       </li>
       <li>
       <p>
       recommendationId
       </p>
       </li>
       <li>
       <p>
       impression
       </p>
       </li>
aws-java-sdk-personalizeevents/src/main/java/com/amazonaws/services/personalizeevents/model/Event.java