parameters: (self, parallel_readouts=None)
docstring: Performs one tree search step.
  
          Each tree search step may potentially expand multiple leaves of the
          game tree, depending on parallel_readouts.
  
          Args:
            parallel_readouts: number of leaves to expand in parallel. If None,
            the number of parallel readouts, the player is free to choose a
            sensible default.
  
          Returns:
            A list of the newly expanded leaves.
docstring_summary: Performs one tree search step.
docstring_tokens: Performs one tree search step .
function: def tree_search(self, parallel_readouts=None):
          """Performs one tree search step.
  
          Each tree search step may potentially expand multiple leaves of the
          game tree, depending on parallel_readouts.
  
          Args:
            parallel_readouts: number of leaves to expand in parallel. If None,
            the number of parallel readouts, the player is free to choose a
            sensible default.
  
          Returns:
            A list of the newly expanded leaves.
          """
function_tokens: def tree_search ( self , parallel_readouts = None ) :