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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 _push_configs_to_nvram(self):
 """ Push the startup-config and private-config content to the NVRAM. """


        startup_config_content = self.startup_config_content
        if startup_config_content:
            nvram_file = self._nvram_file()
            try:
                if not os.path.exists(nvram_file):
                    open(nvram_file, "a").close()
                    nvram_content = None
                else:
                    with open(nvram_file, "rb") as file:
                        nvram_content = file.read()
            except OSError as e:
                raise IOUError("Cannot read nvram file {}: {}".format(nvram_file, e))

            startup_config_content = startup_config_content.encode("utf-8")
            private_config_content = self.private_config_content
            if private_config_content is not None:
                private_config_content = private_config_content.encode("utf-8")
            try:
                nvram_content = nvram_import(nvram_content, startup_config_content, private_config_content, self.nvram)
            except ValueError as e:
                raise IOUError("Cannot push configs to nvram {}: {}".format(nvram_file, e))
            try:
                with open(nvram_file, "wb") as file:
                    file.write(nvram_content)
            except OSError as e:
                raise IOUError("Cannot write nvram file {}: {}".format(nvram_file, e))