Layer Estimates:

Layer: test_arcade (ID:0)
Count: 2
Extent:

XMin: 384122.8399
YMin: 345814.093
XMax: 452457.3613
YMax: 401724.155999999
Spatial Reference: 27700 (27700)

Layer: river (ID:1)
Count: 1
Extent:

XMin: 427320.2116
YMin: 376016.088300001
XMax: 462104.2237
YMax: 421629.951099999
Spatial Reference: 27700 (27700)