class_docstr: Generator exploring the tree.
  
  Nodes are ordered by value and expanded in order.
  The number of edges passing the node "in parallel" are "active".
class_docstr_tok: ["Generator","exploring","the","tree",".","Nodes","are","ordered","by","value","and","expanded","in","order",".","The","number","of","edges","passing","the","node","``","in","parallel","''","are","``","active","''","."]
docstr: (Re)start exploration from the top.
docstr_tok: ["(","Re",")","start","exploration","from","the","top","."]
code: def reset(self):
      """(Re)start exploration from the top."""
      self.active_nodes = list(self.roots)
      self.active_root_ids = np.arange(len(self.active_nodes))
      self.active_node_values = np.array(
          [n.value for n in self.active_nodes]
      )
      self.active_node_ids = np.array([n.id for n in self.active_nodes])
      assert len(self.active_nodes) == len(self.active_root_ids)
      assert len(self.active_nodes) == len(self.active_node_values)
  
imports: import numpy
  from numpy import log, log1p, exp, logaddexp
  import math
  import sys
  from .utils import resample_equal
  from .ordertest import UniformOrderAccumulator
label_desc: Use image node_id 2 for calling the BreadthFirstIterator obj's underlying member method code with example usage: obj.reset() without return types