code: def prepare_headers(self, http_headers, soap_action):
          
  
          headers = {'Content-Type': 'text/xml; charset="utf-8"'}
          if soap_action is not None:
              headers.update({'SOAPACTION': '"{}"'.format(soap_action)})
          if http_headers is not None:
              headers.update(http_headers)
          return headers
docs: Prepare the http headers for sending.
  
          Add the SOAPACTION header to the others.
  
          Args:
              http_headers (dict): A dict in the form {'Header': 'Value,..}
                  containing http headers to use for the http request.
              soap_action (str): The value of the SOAPACTION header.
  
          Returns:
              dict: headers including the SOAPACTION header.