docs: def export(self, storage_client, overwrite=True):
      
          '''
              a method to export all the records in collection to another platform
              
          :param storage_client: class object with storage client methods
          :return: string with exit message
          '''
          
          title = '%s.export' % self.__class__.__name__
          
      # validate storage client
          method_list = [ 'save', 'load', 'list', 'export', 'delete', 'remove', '_import', 'collection_name' ]
          for method in method_list:
              if not getattr(storage_client, method, None):
                  from labpack.parsing.grammar import join_words
                  raise ValueError('%s(storage_client=...) must be a client object with %s methods.' % (title, join_words(method_list)))
      
      # define copy record function
          def _copy_record(_record, _storage_client):
              record_key = _record['key']
              record_data, record_metadata = self.s3.read_record(self.bucket_name, record_key)
              encryption = ''
              if 'encryption' in record_metadata['metadata'].keys():
                  encryption = record_metadata['metadata']['encryption']
              last_modified = 0.0
              if 'last_modified' in record_metadata['metadata'].keys():
                  try:
                      last_modified = float(record_metadata['metadata']['last_modified'])
                  except:
                      pass
              outcome = _storage_client._import(record_key, record_data, overwrite=overwrite, encryption=encryption, last_modified=last_modified)
              return outcome
              
      # retrieve list of records in bucket
          count = 0
          skipped = 0
          record_list, next_key = self.s3.list_records(self.bucket_name)
          for record in record_list:
              outcome = _copy_record(record, storage_client)
              if outcome:
                  count += 1
              else:
                  skipped += 1
          
      # continue through bucket
          if next_key:
              while next_key:
                  record_list, next_key = self.s3.list_records(self.bucket_name, starting_key=next_key)
                  for record in record_list:
                      outcome = _copy_record(record, storage_client)
                      if outcome:
                          count += 1
                      else:
                          skipped += 1
      
      # report outcome
          from os import path
          plural = ''
          skip_insert = ''
          new_root, new_folder = path.split(storage_client.collection_folder)
          if count != 1:
              plural = 's'
          if skipped > 0:
              skip_plural = ''
              if skipped > 1:
                  skip_plural = 's'
              skip_insert = ' %s record%s skipped to avoid overwrite.' % (str(skipped), skip_plural)
          exit_msg = '%s record%s exported to %s.%s' % (str(count), plural, new_folder, skip_insert)
          return exit_msg