The ornamental design for a testing center, as shown and described.
The claimed design relates to the layout of elements in a tasting center. The internal angled wall separates two workstations from the remainder of the testing center, but still allows for those workstations to be monitored by a proctor in the central proctor station, represented by the larger workstation.
The sole view is a top plan view of a first embodiment of our new design. A second embodiment which is not shown is identical to the first embodiment except that the internal angled wall that separates two of the workstations from the remainder of the testing center would be shown in solid lines and be a part of the claimed design.
The broken line showing of walls, computer display units, chairs and doors is for illustrative purposes only and forms no part of the claimed design.