Show warning when createFont() cannot find a named font

Maybe a print can be helpful for the case where the user try to create a font without extension like .ttfor .otf from unknown font by the system, and Processing use the default font ?

void setup() {
  size(400,400);
  PFont f = createFont("Unknow_font",100); // don't find this font, Processing use default font
  PFont f = createFont("Unknow_font.ttf",100); // return null pointer exception
  // PFont f = createFont("Garamond",100); // find font
  println(f.getName());
}