code: def inner_join(self, *joiners):
          
          def inner_joins(js, current_table):
              for joiner in js:
                  yield (((current_table, joiner['on'][1]),
                          (joiner['table'], joiner['on'][0])))
                  current_table = joiner['table']
  
          self.inner_joins = list(inner_joins(joiners, self.table_name))
          return self
docs: Analog to SQL "INNER JOIN". +joiners+ is a list with entries of the
          form:
  
          {
              'table': <table_name>,
              'on': [<foreign_key>, <local_id>]
          }
  
          Example:
  
          >>> Repo('bs').inner_join(
              {'table': 'cs', on: ['b_id', 'id']}).select("*")
          SELECT bs.* FROM bs INNER JOIN cs ON cs.b_id == bs.id