### Question:
WalletTxnParams { public WalletTxnParams amount(Integer amount) { this.amount = amount; return this; }  WalletTxnParams amount(Integer amount); @ApiModelProperty(example = "5000", required = true, value = "取引金額") Integer getAmount(); void setAmount(Integer amount); WalletTxnParams balance(Integer balance); @javax.annotation.Nullable @ApiModelProperty(example = "10000", value = "残高 (銀行口座等)") Integer getBalance(); void setBalance(Integer balance); WalletTxnParams companyId(Integer companyId); @ApiModelProperty(example = "1", required = true, value = "事業所ID") Integer getCompanyId(); void setCompanyId(Integer companyId); WalletTxnParams date(String date); @ApiModelProperty(example = "2018-01-01", required = true, value = "取引日 (yyyy-mm-dd)") String getDate(); void setDate(String date); WalletTxnParams description(String description); @javax.annotation.Nullable @ApiModelProperty(example = "取引内容", value = "取引内容") String getDescription(); void setDescription(String description); WalletTxnParams entrySide(EntrySideEnum entrySide); @ApiModelProperty(example = "income", required = true, value = "入金／出金 (入金: income, 出金: expense)") EntrySideEnum getEntrySide(); void setEntrySide(EntrySideEnum entrySide); WalletTxnParams walletableId(Integer walletableId); @ApiModelProperty(example = "1", required = true, value = "口座ID") Integer getWalletableId(); void setWalletableId(Integer walletableId); WalletTxnParams walletableType(WalletableTypeEnum walletableType); @ApiModelProperty(example = "bank_account", required = true, value = "口座区分 (銀行口座: bank_account, クレジットカード: credit_card, 現金: wallet)") WalletableTypeEnum getWalletableType(); void setWalletableType(WalletableTypeEnum walletableType); @Override boolean equals(java.lang.Object o); @Override int hashCode(); @Override String toString(); static final String SERIALIZED_NAME_AMOUNT; static final String SERIALIZED_NAME_BALANCE; static final String SERIALIZED_NAME_COMPANY_ID; static final String SERIALIZED_NAME_DATE; static final String SERIALIZED_NAME_DESCRIPTION; static final String SERIALIZED_NAME_ENTRY_SIDE; static final String SERIALIZED_NAME_WALLETABLE_ID; static final String SERIALIZED_NAME_WALLETABLE_TYPE; }### Answer:
@Test public void amountTest() { }