Sentence:  In order to be saved , plasticity had had to be isolated ; and as the aspect of the subject was transposed into those <WSD>clusters</WSD> of more or less interchangeable and contour obliterating facet-planes by which plasticity was isolated under the Cubist method , the subject itself became largely unrecognizable . 
Meaning of the word marked with <WSD> tags:  a grouping of a number of similar things