class_docstr: Logarithm of the sum of exponentiations of the inputs in base-2.
  
  Helper class for use with e.g. numpy.logaddexp2
  
  See Also
  ========
  
  https://numpy.org/doc/stable/reference/generated/numpy.logaddexp2.html
code: def _eval_rewrite_as_log(self, x1, x2, **kwargs):
      return _logaddexp2(x1, x2)
  
imports: from sympy.core.function import Add, ArgumentIndexError, Function
  from sympy.core.power import Pow
  from sympy.core.singleton import S
  from sympy.core.sorting import default_sort_key
  from sympy.functions.elementary.exponential import exp, log
label_desc: Use image node_id 3 for calling the logaddexp2 obj's underlying member method code with example usage: obj._eval_rewrite_as_log(x1, x2) and returns: _logaddexp2