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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _create_proxy(proxy_setting):
 """Create a Network proxy for the given proxy settings."""

        proxy = QNetworkProxy()
        proxy_scheme = proxy_setting['scheme']
        proxy_host = proxy_setting['host']
        proxy_port = proxy_setting['port']
        proxy_username = proxy_setting['username']
        proxy_password = proxy_setting['password']
        proxy_scheme_host = '{0}://{1}'.format(proxy_scheme, proxy_host)
        proxy.setType(QNetworkProxy.HttpProxy)

        if proxy_scheme_host:
            # proxy.setHostName(proxy_scheme_host)  # does not work with scheme
            proxy.setHostName(proxy_host)

        if proxy_port:
            proxy.setPort(proxy_port)

        if proxy_username:
            proxy.setUser(proxy_username)

        if proxy_password:
            proxy.setPassword(proxy_password)

        return proxy