human
Give me a the Python program you requested given the following:
Complete the below
def http_get(uri):

    ''''Performs a GET request
    :param uri: The URL to perform a GET request to
    :return: A deferred firing the body of the response.
    :raises HttpError: When the HTTP response code is not OK (i.e. not the HTTP Code 200)'
    '''
assistant
#Here is the Python program you requested.
    def _on_response(response):
        if (response.code == http.OK):
            return readBody(response)
        raise HttpError(response)
    agent = Agent(reactor)
    deferred = agent.request('GET', uri, Headers({'User-Agent': [('Tribler    ' + version_id)]}), None)
    deferred.addCallback(_on_response)
    return deferred