public MergeDeveloperIdentitiesRequest withSourceUserIdentifier(String sourceUserIdentifier) {
        setSourceUserIdentifier(sourceUserIdentifier);
        return this;
    }
<p>
User identifier for the source user. The value should be a <code>DeveloperUserIdentifier</code>.
</p>

@param sourceUserIdentifier
       User identifier for the source user. The value should be a <code>DeveloperUserIdentifier</code>.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-cognitoidentity/src/main/java/com/amazonaws/services/cognitoidentity/model/MergeDeveloperIdentitiesRequest.java