Get Twitter Home Timeline via C#

TweetHttpClient.cs

public class TweetHttpClient : ITwitterHttpClient
{
    public TweetHttpClient()
    {
        _httpClient = new HttpClient
        {
            BaseAddress = new Uri("https://api.twitter.com/")
        };
    }

    public async Task<List<TweetStatus>> GetUserTimeLineAsync(string screenName, int count)
    {
        var accessToken = await GetAccessTokenAsync();
        _httpClient.DefaultRequestHeaders.Clear();
        _httpClient.DefaultRequestHeaders.Add("Authorization", "Bearer " + accessToken);
        var response = await _httpClient.GetAsync($"1.1/statuses/user_timeline.json?screen_name={screenName}&count={count}");
        var json = await response.Content.ReadAsStringAsync();

        return JsonConvert.DeserializeObject<List<TweetStatus>>(json);
    }

    #region Private methods

    private async Task<string> GetAccessTokenAsync()
    {
        var consumerKeyUrlEncode = Uri.EscapeDataString(ConfigurationSetting.TwitterConsumerKey);
        var consumerSecretUrlEncode = Uri.EscapeDataString(ConfigurationSetting.TwitterConsumerSecret);
        var concatConsumerKeyAndSecret = string.Concat(consumerKeyUrlEncode, ":", consumerSecretUrlEncode);
        var base64ConcatConsumerKeyAndSecret = Convert.ToBase64String(Encoding.UTF8.GetBytes(concatConsumerKeyAndSecret));

        _httpClient.DefaultRequestHeaders.Clear();
        _httpClient.DefaultRequestHeaders.Add("Authorization", "Basic " + base64ConcatConsumerKeyAndSecret);
        var bearerToken =
            await _httpClient.PostAsync("oauth2/token", new FormUrlEncodedContent(new[] { new KeyValuePair<string, string>("grant_type", "client_credentials"), }));
        var accessToken = await bearerToken.Content.ReadAsStringAsync();
        var obj = JsonConvert.DeserializeAnonymousType(accessToken, new { access_token = accessToken });
        return obj.access_token;
    }

    #endregion

    #region Fields

    private readonly HttpClient _httpClient;

    #endregion
}