Returns the background image or skin of a report element as a binary stream.
GET /documents/<documentID>/reports/<reportID>/elements/<elementID>/background
The response type depends on the background image or skin format, for example:
Use image/* if you do not know the background format.
An error is thrown when:
GET /documents/9199/reports/154769/elements/289477/background
Response:
Content-Type: image/png HTTP Response Code: 200