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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 _validate_marker_name(self, marker_name):
 """Validates marker name, raising error if invalid."""


        if marker_name not in self.valid_marker_names:
            raise InvalidMarkerNameError(
                "{} is not a valid marker name".format(marker_name)
            )

        return marker_name