private async Task<bool> SignInUser()
		{
			var userIsLogged = false;
			var preferenceHelper = new SharedPreferencesHelper(this);
			var bearerToken = (string)preferenceHelper.GetSharedPreference<string>(SharedPreferencesKeys.BEARER_TOKEN);
			if (bearerToken != null)
			{
				userIsLogged = await signInService.SignInUserWithBearerToken(new TokenModel { Token = bearerToken });
			}
			if (!userIsLogged)
			{
				if (AccessToken.CurrentAccessToken != null && AccessToken.CurrentAccessToken.Token != null)
				{
					var facebookToken = new FacebookTokenViewModel { FacebookToken = AccessToken.CurrentAccessToken.Token };
					var tokenModel = await signInService.SignInUserWithFacebookToken(facebookToken);
					if (tokenModel != null)
					{
						preferenceHelper.SetSharedPreference<string>(SharedPreferencesKeys.BEARER_TOKEN, tokenModel.Token);
						userIsLogged = true;
					}
				}
			}

			return userIsLogged;
		}
		private async Task<bool> LoginWithFacebook() {
			var userIsLogged = false;
			var fbTokenViewModel = new FacebookTokenViewModel { FacebookToken = AccessToken.CurrentAccessToken.Token };
			var bearerToken = await this.signInService.SignInUserWithFacebookToken(fbTokenViewModel);
			if (bearerToken != null) {
				preferenceHelper.SetSharedPreference<string>(SharedPreferencesKeys.BEARER_TOKEN, bearerToken.Token);
				userIsLogged = true;
			}
			return userIsLogged;
		}