code: def _validate_input_para(self, para, column_names):
          
          lower_case_valid_class = [et.lower() for et in self.valid_class]
  
          alt_valid_names = {
              'name_short': ['short', 'short_name', 'name', 'names'],
              'name_official': ['official', 'long_name', 'long'],
              'UNcode': ['un', 'unnumeric'],
              'ISOnumeric': ['isocode'],
              }
  
          for item in alt_valid_names.items():
              if para.lower() in item[1]:
                  para = item[0]
  
          try:
              validated_para = self.valid_class[
                  lower_case_valid_class.index(para.lower())]
          except ValueError:
              raise KeyError(
                  '{} is not a valid country classification'.format(para))
  
          return validated_para
docs: Convert the input classificaton para to the correct df column name
  
          Parameters
          ----------
  
          para : string
          column_names : list of strings
  
          Returns
          -------
  
          validated_para : string
              Converted to the case used in the country file