src/vs/editor/contrib/find/browser/replacePattern.ts/ReplacePiece/constructor
class ReplacePiece:	private constructor(staticValue: string | null, matchIndex: number, caseOps: string[] | null) {
		this.staticValue = staticValue;
		this.matchIndex = matchIndex;
		if (!caseOps || caseOps.length === 0) {
			this.caseOps = null;
		} else {
			this.caseOps = caseOps.slice(0);
		}
	}