code: public ArrayList<String> organizationName_service_exchangeService_externalContact_GET(String organizationName, String exchangeService, String displayName, String externalEmailAddress, String firstName, Long id, String lastName) throws IOException {
  		String qPath = "/email/exchange/{organizationName}/service/{exchangeService}/externalContact";
  		StringBuilder sb = path(qPath, organizationName, exchangeService);
  		query(sb, "displayName", displayName);
  		query(sb, "externalEmailAddress", externalEmailAddress);
  		query(sb, "firstName", firstName);
  		query(sb, "id", id);
  		query(sb, "lastName", lastName);
  		String resp = exec(qPath, "GET", sb.toString(), null);
  		return convertTo(resp, t1);
  	}
docs: External contacts for this service
  
  REST: GET /email/exchange/{organizationName}/service/{exchangeService}/externalContact
  @param lastName [required] Filter the value of lastName property (like)
  @param displayName [required] Filter the value of displayName property (like)
  @param id [required] Filter the value of id property (like)
  @param externalEmailAddress [required] Filter the value of externalEmailAddress property (like)
  @param firstName [required] Filter the value of firstName property (like)
  @param organizationName [required] The internal name of your exchange organization
  @param exchangeService [required] The internal name of your exchange service