Cannot get the result from newAsyncHttpClient?

[Ward]

Nim Compiler Version 0.19.0 [Windows: amd64]

Consider this code: 
    
    
    import asyncdispatch, httpclient
    
    var client = newAsyncHttpClient()
    var fut1 = client.getContent("https://www.google.com";)
    echo waitFor fut1
    var fut2 = client.getContent("https://www.google.com";)
    echo waitFor fut2
    
    
    Run

It's works, however:
    
    
    import asyncdispatch, httpclient
    
    var client = newAsyncHttpClient()
    var fut1 = client.getContent("https://www.google.com";)
    var fut2 = client.getContent("https://www.google.com";)
    echo waitFor fut1
    echo waitFor fut2
    
    
    Run

It cannot get the result, why?