def read(self):
swagger = None<EOL>if self.definition_body:<EOL><INDENT>swagger = self._read_from_definition_body()<EOL><DEDENT>if not swagger and self.definition_uri:<EOL><INDENT>swagger = self._download_swagger(self.definition_uri)<EOL><DEDENT>return swagger<EOL>
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