Check the environment and merge it with some settings.

        :rtype: dict

def merge_environment_settings(self, url, proxies, stream, verify, cert):
        """
        Check the environment and merge it with some settings.

        :rtype: dict
        """
        # Gather clues from the surrounding environment.
        if self.trust_env:
            # Set environment's proxies.
            no_proxy = proxies.get('no_proxy') if proxies is not None else None
            env_proxies = get_environ_proxies(url, no_proxy=no_proxy)
            for (k, v) in env_proxies.items():
                proxies.setdefault(k, v)

            # Look for requests environment configuration and be compatible
            # with cURL.
            if verify is True or verify is None:
                verify = (os.environ.get('REQUESTS_CA_BUNDLE') or
                          os.environ.get('CURL_CA_BUNDLE'))

        # Merge all the kwargs.
        proxies = merge_setting(proxies, self.proxies)
        stream = merge_setting(stream, self.stream)
        verify = merge_setting(verify, self.verify)
        cert = merge_setting(cert, self.cert)

        return {'verify': verify, 'proxies': proxies, 'stream': stream,
                'cert': cert}