code: function getContact($contactId, $checksum, $standard_fields = array(), $custom_fields = array(), $ignoreChecksum = false)
      {
          $queryParameters = array(
              'id' => $contactId,
              'checksum' => $checksum,
              'standard_field' => $standard_fields,
              'ignore_checksum' => $ignoreChecksum ? "true" : "false"
          );
  
          $queryParameters = $this->appendArrayFields($queryParameters, 'custom_field', $custom_fields);
  
          return $this->get('contacts/contact', $queryParameters);
      }
docs: Return a contact using the maileon contact id. This resource is intended to be used
  in profile update pages to prefill profile update forms. In order to prevent form
  fields manipulation, a checksum of the maileon contact id is required as parameter.
  Please refer to the documentation of the profile update pages for more details
  about how to get the maileon contact id and the corresponding checksum.
  
  @param string $contactId
  the maileon contact id
  @param string $checksum
  the checksum of the maileon contact id
  @param string[] $standard_fields
  the standard fields to retrieve with the contact
  @param string[] $custom_fields
  the custom fields to retrieve with the contact
  @param bool $ignoreChecksum
  if set to true, no checksum is required
  @return \em com_maileon_api_MaileonAPIResult
  the result object of the API call, with a com_maileon_api_contacts_Contact
  available at com_maileon_api_MaileonAPIResult::getResult()
  @throws com_maileon_api_MaileonAPIException
  if there was a connection problem or a server error occurred