extensions/merge-conflict/src/mergeConflictParser.ts/MergeConflictParser/shiftBackOneCharacter
class MergeConflictParser:	private static shiftBackOneCharacter(document: vscode.TextDocument, range: vscode.Position, unlessEqual: vscode.Position): vscode.Position {
		if (range.isEqual(unlessEqual)) {
			return range;
		}

		let line = range.line;
		let character = range.character - 1;

		if (character < 0) {
			line--;
			character = document.lineAt(line).range.end.character;
		}

		return new vscode.Position(line, character);
	}