<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def element_name_by_href(href):
 """ The element href is known, possibly from a reference in an elements json. You want to retrieve the name of this element. :param str href: href of element :return: str name of element, or None """

    if href:
        element = fetch_json_by_href(href)
        if element.json:
            return element.json.get('name')