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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 headers_to_sign(self, http_request):
 """ Select the headers from the request that need to be included in the StringToSign. """

        headers_to_sign = {}
        headers_to_sign = {'Host' : self.host}
        for name, value in http_request.headers.items():
            lname = name.lower()
            if lname.startswith('x-amz'):
                headers_to_sign[name] = value
        return headers_to_sign