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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 get(self, file_path, ref, **kwargs):
 """Retrieve a single file. Args: file_path (str):
 Path of the file to retrieve ref (str):
 Name of the branch, tag or commit **kwargs: Extra options to send to the server (e.g. sudo) Raises: GitlabAuthenticationError: If authentication is not correct GitlabGetError: If the file could not be retrieved Returns: object: The generated RESTObject """

        file_path = file_path.replace('/', '%2F')
        return GetMixin.get(self, file_path, ref=ref, **kwargs)