def balance
      have_key?
      address = @url_private
      body = { "method" => "get_info" }
      h = post_ssl(address, body)
      {
        "jpy"        => {
          "amount"    => BigDecimal.new(h["return"]["deposit"]["jpy"].to_s),
          "available" => BigDecimal.new(h["return"]["funds"]["jpy"].to_s),
        },
        "btc"        => {
          "amount"    => BigDecimal.new(h["return"]["deposit"]["btc"].to_s),
          "available" => BigDecimal.new(h["return"]["funds"]["btc"].to_s),
        },
        "ltimestamp" => Time.now.to_i,
      }
    end
def balance
      have_key?
      address = @url_private
      body = { "method" => "get_info" }
      h = post_ssl(address, body)
      {
        "jpy"        => {
          "amount"    => BigDecimal.new(h["return"]["deposit"]["jpy"].to_s),
          "available" => BigDecimal.new(h["return"]["funds"]["jpy"].to_s),
        },
        "btc"        => {
          "amount"    => BigDecimal.new(h["return"]["deposit"]["btc"].to_s),
          "available" => BigDecimal.new(h["return"]["funds"]["btc"].to_s),
        },
        "ltimestamp" => Time.now.to_i,
      }
    end
API for private user data and trading

 Get account balance.
 @abstract
 @return [hash] account_balance_hash
   jpy: [hash]
      amount: [BigDecimal] 総日本円
      available: [BigDecimal] 取引可能な日本円
   btc [hash]
      amount: [BigDecimal] 総BTC
      available: [BigDecimal] 取引可能なBTC
   ltimestamp: [int] ローカルタイムスタンプ