class_docstr: Find a new point with a series of small steps
class_docstr_tok: ["Find","a","new","point","with","a","series","of","small","steps"]
code: def reflect_at(self, j, xk, vk, sign, Llast):
      self.nreflections += 1
      if Llast is not None:
          # we can go about our merry way.
          self.contourpath.add(j, xk, vk, Llast)
      else:
          # we are stuck and have to give up this direction
          if self.plot:
              plt.plot(xk[0], xk[1], "s", mfc="None", mec="r", ms=10)
          if sign == 1:
              self.contourpath.samplingpath.fwd_possible = False
          else:
              self.contourpath.samplingpath.rwd_possible = False
  
imports: import numpy
  from numpy.linalg import norm
  import matplotlib.pyplot
  from .samplingpath import angle, extrapolate_ahead
label_desc: Use image node_id 4 for calling the ClockedStepSampler obj's underlying member method code with example usage: obj.reflect_at(j, xk, vk, sign, Llast) without return types