Set manual overrides on AWS service limits, i.e. if you
        had limits increased by AWS support. This takes a dict in
        the same form as that returned by :py:meth:`~.get_limits`,
        i.e. service_name (str) keys to nested dict of limit_name
        (str) to limit value (int) like:
        ::

            {
                'EC2': {
                  'Running On-Demand t2.micro Instances': 1000,
                  'Running On-Demand r3.4xlarge Instances': 1000,
                }
            }

        Internally, for each limit override for each service in
        ``override_dict``, this method calls
        :py:meth:`._AwsService.set_limit_override` on the corresponding
        _AwsService instance.

        Explicitly set limit overrides using this method will take
        precedence over default limits. They will also take precedence over
        limit information obtained via Trusted Advisor, unless ``override_ta``
        is set to ``False``.

        :param override_dict: dict of overrides to default limits
        :type override_dict: dict
        :param override_ta: whether or not to use this value even if Trusted
          Advisor supplies limit information
        :type override_ta: bool
        :raises: :py:exc:`ValueError` if limit_name is not known to the
          service instance

def set_limit_overrides(self, override_dict, override_ta=True):
        """
        Set manual overrides on AWS service limits, i.e. if you
        had limits increased by AWS support. This takes a dict in
        the same form as that returned by :py:meth:`~.get_limits`,
        i.e. service_name (str) keys to nested dict of limit_name
        (str) to limit value (int) like:
        ::

            {
                'EC2': {
                  'Running On-Demand t2.micro Instances': 1000,
                  'Running On-Demand r3.4xlarge Instances': 1000,
                }
            }

        Internally, for each limit override for each service in
        ``override_dict``, this method calls
        :py:meth:`._AwsService.set_limit_override` on the corresponding
        _AwsService instance.

        Explicitly set limit overrides using this method will take
        precedence over default limits. They will also take precedence over
        limit information obtained via Trusted Advisor, unless ``override_ta``
        is set to ``False``.

        :param override_dict: dict of overrides to default limits
        :type override_dict: dict
        :param override_ta: whether or not to use this value even if Trusted
          Advisor supplies limit information
        :type override_ta: bool
        :raises: :py:exc:`ValueError` if limit_name is not known to the
          service instance
        """
        for svc_name in override_dict:
            for lim_name in override_dict[svc_name]:
                self.services[svc_name].set_limit_override(
                    lim_name,
                    override_dict[svc_name][lim_name],
                    override_ta=override_ta
                )