public void setRelatedContactId(String relatedContactId) {
        this.relatedContactId = relatedContactId;
    }
<p>
The unique identifier for an Amazon Connect contact. This identifier is related to the chat starting.
</p>
<note>
<p>
You cannot provide data for both RelatedContactId and PersistentChat.
</p>
</note>

@param relatedContactId
       The unique identifier for an Amazon Connect contact. This identifier is related to the chat starting.</p>
       <note>
       <p>
       You cannot provide data for both RelatedContactId and PersistentChat.
       </p>
aws-java-sdk-connect/src/main/java/com/amazonaws/services/connect/model/StartChatContactRequest.java