instance method pool_for

# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 594
      def pool_for(owner)
        owner_to_pool.fetch(owner.name) {
          if ancestor_pool = pool_from_any_process_for(owner)
            # A connection was established in an ancestor process that must have
            # subsequently forked. We can't reuse the connection, but we can copy
            # the specification and establish a new connection with it.
            establish_connection owner, ancestor_pool.spec
          else
            owner_to_pool[owner.name] = nil
          end
        }
      end