How to use the jira.utils.CaseInsensitiveDict function in jira

logging.warning(
                "%s was not opened in 'rb' mode, attaching file may fail." % attachment.name)

        url = self._get_url('issue/' + str(issue) + '/attachments')

        fname = filename
        if not fname:
            fname = os.path.basename(attachment.name)

        if 'MultipartEncoder' not in globals():
            method = 'old'
            r = self._session.post(
                url,
                files={
                    'file': (fname, attachment, 'application/octet-stream')},
                headers=CaseInsensitiveDict({'content-type': None, 'X-Atlassian-Token': 'nocheck'}))
        else:
            method = 'MultipartEncoder'

            def file_stream():
                return MultipartEncoder(
                    fields={
                        'file': (fname, attachment, 'application/octet-stream')})
            m = file_stream()
            r = self._session.post(
                url, data=m, headers=CaseInsensitiveDict({'content-type': m.content_type, 'X-Atlassian-Token': 'nocheck'}), retry_data=file_stream)

        js = json_loads(r)
        if not js or not isinstance(js, collections.Iterable):
            raise JIRAError("Unable to parse JSON: %s" % js)
        attachment = Attachment(self._options, self._session, js[0])
        if attachment.size == 0:

payload = {'name': name,
                   'key': key,
                   'keyEdited': 'false',
                   # 'projectTemplate': 'com.atlassian.jira-core-project-templates:jira-issuetracking',
                   # 'permissionScheme': '',
                   'projectTemplateWebItemKey': template_key,
                   'projectTemplateModuleKey': template_key,
                   'lead': assignee,
                   # 'assigneeType': '2',
                   }

        if self._version[0] > 6:
            # JIRA versions before 7 will throw an error if we specify type parameter
            payload['type'] = type

        headers = CaseInsensitiveDict(
            {'Content-Type': 'application/x-www-form-urlencoded'})

        r = self._session.post(url, data=payload, headers=headers)

        if r.status_code == 200:
            r_json = json_loads(r)
            return r_json

        f = tempfile.NamedTemporaryFile(
            suffix='.html', prefix='python-jira-error-create-project-', delete=False)
        f.write(r.text)

        if self.logging:
            logging.error(
                "Unexpected result while running create project. Server response saved in %s for further investigation [HTTP response=%s]." % (
                    f.name, r.status_code))

    def _load(self, url, headers=CaseInsensitiveDict(), params=None, path=None):
        """ Load a resource.

        :type url: str
        :type headers: CaseInsensitiveDict
        :type params: Optional[Dict[str,str]]
        :type path: Optional[str]

        """
        r = self._session.get(url, headers=headers, params=params)
        try:
            j = json_loads(r)
        except ValueError as e:
            logging.error("%s:\n%s" % (e, r.text))
            raise e
        if path:
            j = j[path]

def _gain_sudo_session(self, options, destination):
        url = self._options['server'] + '/secure/admin/WebSudoAuthenticate.jspa'

        if not self._session.auth:
            self._session.auth = get_netrc_auth(url)

        payload = {
            'webSudoPassword': self._session.auth[1],
            'webSudoDestination': destination,
            'webSudoIsPost': 'true'}

        payload.update(options)

        return self._session.post(
            url, headers=CaseInsensitiveDict({'content-type': 'application/x-www-form-urlencoded'}), data=payload)

def _default_headers(self, user_headers):
        # result = dict(user_headers)
        # result['accept'] = 'application/json'
        return CaseInsensitiveDict(
            self._options["headers"].items() + user_headers.items()
        )