remove_connection

# File activerecord/lib/active_record/connection_handling.rb, line 343
    def remove_connection
      name = @connection_specification_name if defined?(@connection_specification_name)

      # if removing a connection that has a pool, we reset the
      # connection_specification_name so it will use the parent
      # pool.
      if connection_handler.retrieve_connection_pool(name, role: current_role, shard: current_shard)
        self.connection_specification_name = nil
      end

      connection_handler.remove_connection_pool(name, role: current_role, shard: current_shard)
    end