public void setIdentityId(String identityId) {
        this.identityId = identityId;
    }
<p>
A unique identifier in the format REGION:GUID.
</p>

@param identityId
       A unique identifier in the format REGION:GUID.
aws-java-sdk-cognitoidentity/src/main/java/com/amazonaws/services/cognitoidentity/model/GetOpenIdTokenForDeveloperIdentityRequest.java