def get(key)
      pool = @_sessions[key]
      unless pool
        @mutex.synchronize do
          unless @shutdown
            @reaper = spawn_reaper if @reaper.nil?
            unless pool = @_sessions[key]
              settings = @_staged[key]
              clnt_blk = (settings[1] || @default_client)
              op = @pool_options.merge(settings[0])
              op[:sessions_key] = key
              op[:name] = "#{@name} - #{key}"
              pool = @_sessions[key] = HotTub::Pool.new(op, &clnt_blk)
            end
          end
        end
      end
      pool
    end
def get(key)
      pool = @_sessions[key]
      unless pool
        @mutex.synchronize do
          unless @shutdown
            @reaper = spawn_reaper if @reaper.nil?
            unless pool = @_sessions[key]
              settings = @_staged[key]
              clnt_blk = (settings[1] || @default_client)
              op = @pool_options.merge(settings[0])
              op[:sessions_key] = key
              op[:name] = "#{@name} - #{key}"
              pool = @_sessions[key] = HotTub::Pool.new(op, &clnt_blk)
            end
          end
        end
      end
      pool
    end
Returns a HotTub::Pool for the given key. If a session
 is not found and the is a default_client set, a session will
 be created for the key using the default_client.