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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 read(self):
 """ Gets the Swagger document from either of the given locations. If we fail to retrieve or parse the Swagger file, this method will return None. Returns ------- dict: Swagger document. None, if we cannot retrieve the document """


        swagger = None

        # First check if there is inline swagger
        if self.definition_body:
            swagger = self._read_from_definition_body()

        if not swagger and self.definition_uri:
            # If not, then try to download it from the given URI
            swagger = self._download_swagger(self.definition_uri)

        return swagger