code: public Person findByEmail(String email) throws JinxException {
      JinxUtils.validateParams(email);
      Map<String, String> params = new TreeMap<>();
      params.put("method", "flickr.people.findByEmail");
      params.put("find_email", email);
      return jinx.flickrGet(params, Person.class, false);
    }
docs: Return a user's id and username, given their email address
  <br>
  This method does not require authentication.
  <br>
  This returns the Person object, but only the userId and username will be populated.
  
  @param email (Required) The email address of the user to find (may be primary or secondary).
  @return object with information about the person.
  @throws JinxException if required parameters are missing, or if there are any errors.
  @see <a href="https://www.flickr.com/services/api/flickr.people.findByEmail.html">flickr.people.findByEmail</a>