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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 _load_script(self):
 """Loads the script from the filesystem :raises exceptions.IOError: if the script file could not be opened """

        script_text = filesystem.read_file(self.path, self.filename)

        if not script_text:
            raise IOError("Script file could not be opened or was empty: {0}"
                          "".format(os.path.join(self.path, self.filename)))
        self.script = script_text