parameters: (self)
docstring: The default is the test node that appears after the `=`. Is `None` in
          case no default is present.
docstring_summary: The default is the test node that appears after the `=`. Is `None` in
          case no default is present.
docstring_tokens: The default is the test node that appears after the = . Is None in case no default is present .
function: def default(self):
          """
          The default is the test node that appears after the `=`. Is `None` in
          case no default is present.
          """
          has_comma = self.children[-1] == ','
          try:
              if self.children[-2 - int(has_comma)] == '=':
                  return self.children[-1 - int(has_comma)]
          except IndexError:
              return None
function_tokens: def default ( self ) : has_comma = self . children [ - 1 ] == ',' try : if self . children [ - 2 - int ( has_comma ) ] == '=' : return self . children [ - 1 - int ( has_comma ) ] except IndexError : return None