Is indexing into the `rebuiltExtendedShares` necessary?

[rootulp]

Context

rsmt2d/extendeddatacrossword.go

Lines 266 to 270 in f166196

	// Otherwise copy them from the EDS.
	startIndex := len(shares) - int(eds.originalDataWidth)
	rebuiltShares = append(
	rebuiltShares[0:eds.originalDataWidth],
	shares[startIndex:]...,

Question

Is indexing into rebuiltExtendedShares necessary? It appears to only contain the parity shares so I would expect this to be sufficient:

-		startIndex := len(rebuiltExtendedShares) - int(eds.originalDataWidth)
-		rebuiltShares = append(
-			rebuiltShares[0:eds.originalDataWidth],
-			rebuiltExtendedShares[startIndex:]...,
-		)
+		rebuiltShares = append(rebuiltShares[0:eds.originalDataWidth], rebuiltExtendedShares...)

[rootulp]

To elaborate, it appears sufficient b/c he rebuiltExtendedShares are the output of Encode which only returns the parity shares.