src/vs/editor/common/services/editorSimpleWorker.ts/MirrorModel/_validateRange
class MirrorModel:	private _validateRange(range: IRange): IRange {

		const start = this._validatePosition({ lineNumber: range.startLineNumber, column: range.startColumn });
		const end = this._validatePosition({ lineNumber: range.endLineNumber, column: range.endColumn });

		if (start.lineNumber !== range.startLineNumber
			|| start.column !== range.startColumn
			|| end.lineNumber !== range.endLineNumber
			|| end.column !== range.endColumn) {

			return {
				startLineNumber: start.lineNumber,
				startColumn: start.column,
				endLineNumber: end.lineNumber,
				endColumn: end.column
			};
		}

		return range;
	}