public Account createAccount(String name, String email_address, Map<String, String> meta)
     throws HTTPError {
   Map<String, Object> payload = new HashMap<String, Object>();
   payload.put("email_address", email_address);
   if (meta != null) payload.put("meta", meta);
   return accounts.create(payload);
 }
 public Account createBuyerAccount(
     String name, String email_address, String card_uri, Map<String, String> meta)
     throws HTTPError {
   Map<String, Object> payload = new HashMap<String, Object>();
   payload.put("card_uri", card_uri);
   if (name != null) payload.put("name", name);
   if (email_address != null) payload.put("email_address", email_address);
   if (meta != null) payload.put("meta", meta);
   return accounts.create(payload);
 }
 public Account createMerchantAccount(
     String name,
     String email_address,
     String bank_account_uri,
     Map<String, Object> merchant,
     Map<String, String> meta)
     throws HTTPError {
   Map<String, Object> payload = new HashMap<String, Object>();
   payload.put("merchant", merchant);
   payload.put("bank_account_uri", bank_account_uri);
   if (name != null) payload.put("name", name);
   if (email_address != null) payload.put("email_address", email_address);
   if (meta != null) payload.put("meta", meta);
   return accounts.create(payload);
 }