public function create($fieldType, $uniqueName) {
        $data = Values::of(array('FieldType' => $fieldType, 'UniqueName' => $uniqueName, ));

        $payload = $this->version->create(
            'POST',
            $this->uri,
            array(),
            $data
        );

        return new FieldInstance(
            $this->version,
            $payload,
            $this->solution['assistantSid'],
            $this->solution['taskSid']
        );
    }