code: def nearest_neighbor(x, tSet):
      
      assert isinstance(x, tuple) and isinstance(tSet, dict)
      current_key = ()
      min_d = float('inf')
      for key in tSet:
          d = distance(x, key)
          if d < min_d:
              min_d = d
              current_key = key
      return tSet[current_key]
docs: [summary]
      Implements the nearest neighbor algorithm
  
      Arguments:
          x {[tupel]} -- [vector]
          tSet {[dict]} -- [training set]
  
      Returns:
          [type] -- [result of the AND-function]