preprocessBufferViews( bufferViewHeaders = [], bufferHeaders ) {

		for ( let i = 0; i < bufferViewHeaders.length; i ++ ) {

			const bufferViewHeader = bufferViewHeaders[ i ];
			bufferViewHeader.bufferHeader = bufferHeaders[ bufferViewHeader.buffer ];
			bufferViewHeader.isActive = false;
			// Keep the external flag for potential use in requestActiveBuffers
			bufferViewHeader.isExternal = bufferViewHeader.bufferHeader.isExternal;

		}
		return bufferViewHeaders;

	}
Iterate the list of buffer views from the subtree JSON and add the
isActive flag. Also save a reference to the bufferHeader.

@param {Object[]} [bufferViewHeaders=[]] The JSON from subtree.bufferViews.
@param {BufferHeader[]} bufferHeaders The preprocessed buffer headers.
@returns {BufferViewHeader[]} The same array of bufferView headers with additional fields.
@private