public function testFormatsStruct()
{
$value = 'test';
$struct = [$value => [$value => $value]];
$expected = ['fields' => [['key' => $value, 'value' => ['struct_value' => ['fields' => [['key' => $value, 'value' => ['string_value' => $value]]]]]]]];
$this->assertEquals($expected, $this->implementation->call('formatStructForApi', [$struct]));
}