src/vs/editor/common/cursor/cursorTypeOperations.ts/TypeOperations/_distributePasteToCursors
class TypeOperations:	private static _distributePasteToCursors(config: CursorConfiguration, selections: Selection[], text: string, pasteOnNewLine: boolean, multicursorText: string[]): string[] | null {
		if (pasteOnNewLine) {
			return null;
		}

		if (selections.length === 1) {
			return null;
		}

		if (multicursorText && multicursorText.length === selections.length) {
			return multicursorText;
		}

		if (config.multiCursorPaste === 'spread') {
			// Try to spread the pasted text in case the line count matches the cursor count
			// Remove trailing \n if present
			if (text.charCodeAt(text.length - 1) === CharCode.LineFeed) {
				text = text.substr(0, text.length - 1);
			}
			// Remove trailing \r if present
			if (text.charCodeAt(text.length - 1) === CharCode.CarriageReturn) {
				text = text.substr(0, text.length - 1);
			}
			const lines = strings.splitLines(text);
			if (lines.length === selections.length) {
				return lines;
			}
		}

		return null;
	}