code: def find_val_for_first_bf_l_meta(d, prop_name):
      
      m_list = d.get('meta')
      if not m_list:
          return None
      if not isinstance(m_list, list):
          m_list = [m_list]
      for m_el in m_list:
          if m_el.get('@property') == prop_name:
              return extract_meta(m_el)
      return None
docs: Returns the $ value of the first meta element with
      the @property that matches @prop_name (or None).