code: def get(self, option, default=undefined, cast=undefined):
          
          if option in self.repository:
              value = self.repository.get(option)
          else:
              value = default
  
          if isinstance(value, Undefined):
              raise UndefinedValueError('%s option not found and default value was not defined.' % option)
  
          if isinstance(cast, Undefined):
              cast = lambda v: v  # nop
          elif cast is bool:
              cast = self._cast_boolean
  
          return cast(value)
docs: Return the value for option or default if defined.