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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 write_xsd(cls) -> None: """Write the complete base schema file `HydPyConfigBase.xsd` based on the template file `HydPyConfigBase.xsdt`. Method |XSDWriter.write_xsd| adds model specific information to the general information of template file `HydPyConfigBase.xsdt` regarding reading and writing of time series data and exchanging parameter and sequence values e.g. during calibration. The following example shows that after writing a new schema file, method |XMLInterface.validate_xml| does not raise an error when either applied on the XML configuration files `single_run.xml` or `multiple_runs.xml` of the `LahnH` example project: False True """

        with open(cls.filepath_source) as file_:
            template = file_.read()
        template = template.replace(
            '<!--include model sequence groups-->', cls.get_insertion())
        template = template.replace(
            '<!--include exchange items-->', cls.get_exchangeinsertion())
        with open(cls.filepath_target, 'w') as file_:
            file_.write(template)