我需要一个代码来获取某些公司的电子邮件使用php中的freebase API

我只知道公司名称和国家。任何人都可以提供一个php代码示例。运行此代码时，我得到一个未找到的错误属性，请发送电子邮件联系

<?php
  $service_url = 'https://www.googleapis.com/freebase/v1/search';
  $params = array(
    'query' => 'Emirates',
    'key' => "My-Key",
    'filter' => '(all type:/business/business_operation)',
    "output" => '(/organization/email_contact )',
//    "result" => array(
//      "/organization/organization/email" => [],
//      "name" => "Freebase Staff",
//      "id" => "/business/business_operation"
//    )
  );
  $url = $service_url . '?' . http_build_query($params);
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
  $response = json_decode(curl_exec($ch), true);
  curl_close($ch);
  print "<pre>";print_r($response);print "</pre>";
?>

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尝试更改输出字段参数值：

输出=>'/organization/email_contact'到输出=> '所有/组织/电子邮件\u联系人'