message: Add removeCharacters() to Position
diff: @@ -83,6 +83,10 @@ class Position {
  return new Position(this.line, this.character + characters);
  }
  + removeCharacters(characters: number): Position {
  + return new Position(this.line, this.character - characters);
  + }
  +
  putAtSameCharacter(position: Position): Position {
  return new Position(this.line, position.character);
  }
  