code: def _boundary2_2002(k, t, r, b, sigma, beta):
      """Computes the second boundary or trigger price for the Bjerksund-Stensland 2002 algorithm."""
  
      # The naming convention will align variables with the variables named in
      # reference [1].
      # [1] https://core.ac.uk/download/pdf/30824897.pdf
  
      b0 = tf.math.maximum(k, (r / (r - b)) * k)
      binfinity = beta / (beta - 1) * k
      ht2 = -(b * t + 2 * sigma * tf.math.sqrt(t)) * (
          k**2 / ((binfinity - b0) * b0)
      )
  
      return b0 + (binfinity - b0) * (1 - tf.math.exp(ht2))
  
imports: from typing import Tuple
  import numpy
  import tensorflow.compat.v2
  from tf_quant_finance import types
  from tf_quant_finance.black_scholes import vanilla_prices
  from tf_quant_finance.math import gradient
  from tf_quant_finance.math import integration
  from tf_quant_finance.math.root_search import newton
label_desc: Use image node_id 10 for calling a global function with example usage: _boundary2_2002(k, t, r, b, sigma, beta) and returns: unknown