code: def fetch_cvparams_values_from_subel(base, subelname, paramnames, ns):
      
      sub_el = basereader.find_element_xpath(base, subelname, ns)
      cvparams = get_all_cvparams(sub_el, ns)
      output = []
      for param in paramnames:
          output.append(fetch_cvparam_value_by_name(cvparams, param))
      return output
docs: Searches a base element for subelement by name, then takes the
      cvParams of that subelement and returns the values as a list
      for the paramnames that match. Value order in list equals input
      paramnames order.