One short question

In the Non-PostScript font classes in mathtext.py the set_canvas_size is
def set_canvas_size(self, w, h):
    'Dimension the drawing canvas; may be a noop'
    self.width = int(w)
    self.height = int(h)
    for font in self.fonts.values():
        font.set_bitmap_size(int(w), int(h))

While in the PS class:
    def set_canvas_size(self, w, h, pswriter):
        'Dimension the drawing canvas; may be a noop'
        self.width = w
        self.height = h
        self.pswriter = pswriter

Why is the float converted to int in the first case, and not in the second?