def _DefaultAlternative(value, default):
  """Returns value or, if evaluating to False, a default value.

  Returns the given value, unless it evaluates to False. In the latter case the
  default value is returned.

  @param value: Value to return if it doesn't evaluate to False
  @param default: Default value
  @return: Given value or the default

  """
  if value:
    return value

  return default