 
 <prompt> Wetin be di technique wey dem use for 64 AD? Based on di question wey dey before dis one, write something wey get di answer inside. E fit be 1 - 20 sentences. Context: <response>: For Rome, Nero and im architects use mosaics cover some parts of walls and ceilings for Domus Aurea, wey dem build for 64 AD, and wall mosaics dey also for Pompeii and oda places wey dey near. But e be like say e no be until Christian era before figural wall mosaics become major form of artistic expression. The Roman church of Santa Costanza, wey serve as mausoleum for one or more of the Imperial family, get both religious mosaic and decorative secular ceiling mosaics for round vault, wey fit be style of contemporary palace decoration. 