message: Add isOneLine to selection
diff: @@ -56,6 +56,10 @@ class Selection {
  return !this.start.isSameLineThan(this.end);
  }
  + get isOneLine(): boolean {
  + return !this.isMultiLines;
  + }
  +
  get height(): number {
  return this.end.line - this.start.line;
  }
  