public static Builder builder() {
        return new Builder();
    }
@return The time until the refresh token expires. Provides the value of 'refresh_token_expires_in' or
if that is null 'refresh_expires_in'. This is to support different IDPs that seem to use different
property names.
stroom-security/stroom-security-openid-api/src/main/java/stroom/security/openid/api/TokenResponse.java