public async Task Update_Account_ExternalIdChanged()
{
string originalExternalId = string.Concat(Guid.NewGuid().ToString("N").Take(16));
string newExternalId = string.Concat(Guid.NewGuid().ToString("N").Take(16));
dynamic account = new ExpandoObject();
account.Name = "New Account";
account.Description = "New Account Description";
account.ExternalId__c = originalExternalId;
var successResponse = await _client.CreateAsync("Account", account);
account.ExternalId__c = newExternalId;
await _client.UpdateAsync("Account", successResponse.Id, account);
var result = await _client.QueryAllFieldsByIdAsync <Account>("Account", successResponse.Id);
Assert.True(result.ExternalId__c.ToString() == newExternalId);
}
