def _build_source_metadata(self, source_element):
        url_element = source_element.find('url')
        odin_url_element = source_element.find('odin')
        citation_element = source_element.find('citation')

        metadata = dict()

        if url_element is not None:
            metadata['source_link'] = url_element.text

        if odin_url_element is not None:
            metadata['source_archive_link'] = odin_url_element.text

        if citation_element is not None:
            metadata['source_description'] = citation_element.text

        return metadata
Method that extracts the relevant metadata from each 'source'
dataset/ETHPy150Open cidles/poio-api/src/poioapi/io/odin.py/Parser._build_source_metadata