human
Solve the following python programming problem given the following code:
def _set_velocity_func(self, func) : 
    "The velocity callback function. The velocity callback function 
        is called each time step, and can be used to set a body's velocity.
        
            ``func(body, gravity, damping, dt) -> None``
            
            Callback Parameters
                body : `Body`
                    Body that should have its velocity calculated
                gravity : `Vec2d`
                    The gravity vector
                damping : float
                    The damping
                dt : float
                    Delta time since last step.
        " 
    def _impl(_, gravity, damping, dt) : 
        return func (self, gravity, damping, dt) 
self._velocity_callback = cp.cpBodyVelocityFunc (_impl) 
    self._bodycontents.velocity_func = _impl._velocity_callback 

    
    

    Fix the buggy line: self._bodycontents.velocity_func = _impl._velocity_callback
assistant
#Here is Python program to fix the buggy line: self.

self._bodycontents.velocity_func = self._velocity_callback