class_docstr: Abstract base class for wait strategies.
code: def __radd__(self, other):
      # make it possible to use multiple waits with the built-in sum function
      if other == 0:
          return self
      return self.__add__(other)
  
imports: import abc
  import random
  import six
  from tenacity import _utils
label_desc: Use image node_id 3 for calling the wait_base obj's underlying member method code with example usage: obj.__radd__(other) and returns: self, self