Set Back-off to Static
        Set the sampler parameters for static back off
    Inputs :
        max_steps :
            maximum optimization steps to be taken
        step_size : 
            the step size of the back-off

def static(self, max_steps, step_size):
        """
    Set Back-off to Static
        Set the sampler parameters for static back off
    Inputs :
        max_steps :
            maximum optimization steps to be taken
        step_size : 
            the step size of the back-off
        """
        self._dynamic = False
        # begin checks      
        try : 
            self._max_steps = int(max_steps)
        except :
            print("Error: Input 1 (max_steps) has to be an int.")
            return 0
        try : 
            assert self._max_steps >= 0
        except : 
            print("Warning: Input 1 (max_steps) has to be non-negative.")
            print("Setting max_steps to 0.")
            self._max_steps = 0

        if max_steps > 0 :
            try : 
                assert step_size == float(step_size)
            except AssertionError :
                print("Warning: Input 2 (step_size) is not a float. Converted.")
                step_size = float(step_size)
            except :
                print("Error: Input 2 (step_size) has to be a float.")
                return 0

            try : 
                assert 0. < step_size < 1.
            except : 
                print("Warning: Input 2 (step_size) has to be between 0 and 1.")
                print("Setting step_size to 0.2.")
                step_size = 0.2
            self._step_size = step_size
            if step_size**max_steps < 10**(-15):
                print("Warning: Back-off gets dangerously small.")