code: def create(self):
          
          if self.bt_table.exists():
              utils.dbg('Table already exists')
              return
  
          max_versions_rule = bigtable_column_family.MaxVersionsGCRule(1)
          self.bt_table.create(column_families={
              METADATA: max_versions_rule,
              TFEXAMPLE: max_versions_rule})
docs: Create the table underlying the queue.
  
          Create the 'metadata' and 'tfexample' column families
          and their properties.