def __init__(self, a, b, *args):
        
        if len(args) == 1:
            self._constraint = cp.cpPivotJointNew(a._body, b._body, args[0])
        elif len(args) == 2:
            self._constraint = cp.cpPivotJointNew2(a._body, b._body, args[0], args[1])
        else:
            raise Exception("You must specify either one pivot point or two anchor points")
            
        self._ccontents = self._constraint.contents
        self._pjc = cp.cast(self._constraint, ct.POINTER(cp.cpPivotJoint)).contents
        self._set_bodies(a,b)
a and b are the two bodies to connect, and pivot is the point in
dataset/ETHPy150Open estevaofon/angry-birds-python/pymunk-4.0.0/pymunk/constraint.py/PivotJoint.__init__