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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 language(self, language):
 """Sets the language of this KernelPushRequest. The language that the kernel is written in # noqa: E501 :param language: The language of this KernelPushRequest. # noqa: E501 :type: str """

        if language is None:
            raise ValueError("Invalid value for `language`, must not be `None`")  # noqa: E501
        allowed_values = ["python", "r", "rmarkdown"]  # noqa: E501
        if language not in allowed_values:
            raise ValueError(
                "Invalid value for `language` ({0}), must be one of {1}"  # noqa: E501
                .format(language, allowed_values)
            )

        self._language = language