QRhiResourceUpdateBatch::copyTexture() documentation is a bit unclear

The documentation of QRhiResourceUpdateBatch::copyTexture() states that "The format of the textures must match". Does "format" here mean format in the narrow sense of QRhiTexture::Format or do other attributes such as sampleCount also have to match? In other words, can the function be used to "collapse" a multi-sample texture to a single-sample texture or not? This is not clear from the documentation.  Please make the documentation more explicit on this point.