def METHOD_NAME(self, tag):
    if tag.startswith(self.github_info["prefix_prod"]):
        return tag.replace(self.github_info["prefix_prod"], "")
    elif tag.startswith(self.github_info["prefix_beta"]):
        return tag.replace(self.github_info["prefix_beta"], "")
    raise ValueError("Could not determine version number from tag {}".format(tag))