old_contents: def export_row(answer):
      obj = answer.answers
      obj['created_at'] = answer.created_at
      obj['updated_at'] = answer.updated_at
      return obj
  
new_contents: def export_row(answer):
      obj = answer.answers
      if 'Contact_number' in obj:
          del obj['Contact_number']
      if 'Full_name' in obj:
          del obj['Full_name']
      if 'Monitor_name' in obj:
          del obj['Monitor_name']
  
      obj['created_at'] = answer.created_at
      obj['updated_at'] = answer.updated_at
      return obj
  
subject: remove personal details