code: public ScaleLevel getLevelFor(Font font, FontRenderContext frc, boolean horizontal, double xy)
      {
          return getLevelFor(font, frc, DoubleTransform.identity(), horizontal, xy);
      }
docs: Returns highest level where drawn labels don't overlap using identity
  transformer
  @param font
  @param frc
  @param horizontal
  @param xy Lines constant value
  @return