'Move turtle to an absolute position.
Aliases: setpos | setposition | goto:
Arguments:
x -- a number      or     a pair/vector of numbers
y -- a number             None
call: goto(x, y)         # two coordinates
--or: goto((x, y))       # a pair (tuple) of coordinates
--or: goto(vec)          # e.g. as returned by pos()
Move turtle to an absolute position. If the pen is down,
a line will be drawn. The turtle\'s orientation does not change.
Example (for a Turtle instance named turtle):
>>> tp = turtle.pos()
>>> tp
(0.00, 0.00)
>>> turtle.setpos(60,30)
>>> turtle.pos()
(60.00,30.00)
>>> turtle.setpos((20,80))
>>> turtle.pos()
(20.00,80.00)
>>> turtle.setpos(tp)
>>> turtle.pos()
(0.00,0.00)'

def goto(self, x, y=None):

    if (y is None):
        self._goto(Vec2D(*x))
    else:
        self._goto(Vec2D(x, y))
