gistfile1.cs

    public interface IHttpCall
    {
        Task<HttpResponseMessage> Execute(HttpClient httpClient);
    }

    public interface IHttpWithResult<T> : IHttpCall
    {
    }
    
    public interface IHttpCallExecutor
    {
        Task Execute(IHttpCall httpCall);
        Task<T> Execute<T>(IHttpWithResult<T> httpCallWithResult) where T : class;
    }
    
    public class SampleCall : IHttpCall
    {
      public Task<HttpResponseMessage> Execute(HttpClient httpClient)
      {
        var requestUri = "/some/relative/path";
        return httpClient.PostAsync(requestUri, new StringContent(string.Empty));       
      }
    }
    
    public class SampleCallWithResult : IHttpCallWithResult<string>
    {
      public Task<HttpResponseMessage> Execute(HttpClient httpClient)
      {
        var requestUri = "/some/relative/path";
        return httpClient.PostAsync(requestUri, new StringContent(string.Empty));       
      }
    }