client = Coinbase::Wallet::Client.new(api_key: ENV["CB_API_KEY"], api_secret: ENV["CB_API_SECRET"])
 buy_price = client.buy_price(currency_pair: 'LTC-USD')["amount"].to_f

client = Coinbase::Wallet::Client.new(api_key: ENV["CB_API_KEY"], api_secret: ENV["CB_API_SECRET"], api_version: '2019-05-29')
account = client.primary_account  #  <-- error
payment_method = client.get_payment_methods()[0]
p "account = #{payment_method}"
p "payment method = #{payment_method}"
sleep
account.sell(amount = @sell_amount, currency = 'LTC', payment_method = payment_method.id)

from coinbase.wallet.client import Client
client = Client(<api_key>,
                <api_secret>,
                api_version='YYYY-MM-DD')

payment_methods = client.get_payment_methods()