@Override
    public String toString() {
        return "TokenResponse{" +
                "idToken='" + idToken + '\'' +
                ", tokenType='" + tokenType + '\'' +
                ", expiresIn=" + expiresIn +
                ", refreshTokenExpiresIn=" + refreshTokenExpiresIn +
                ", accessToken='" + accessToken + '\'' +
                ", refreshToken='" + refreshToken + '\'' +
                '}';
    }
@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