Fetch collection folder contents

        :param folderid: UUID of the folder to list
        :param username: The user to list folders for, if omitted the authenticated user is used
        :param offset: the pagination offset
        :param limit: the pagination limit

def get_collection(self, folderid, username="", offset=0, limit=10):

        """Fetch collection folder contents

        :param folderid: UUID of the folder to list
        :param username: The user to list folders for, if omitted the authenticated user is used
        :param offset: the pagination offset
        :param limit: the pagination limit
        """

        if not username and self.standard_grant_type == "authorization_code":
            response = self._req('/collections/{}'.format(folderid), {
                "offset":offset,
                "limit":limit
            })
        else:
            if not username:
                raise DeviantartError("No username defined.")
            else:
                response = self._req('/collections/{}'.format(folderid), {
                    "username":username,
                    "offset":offset,
                    "limit":limit
                })

        deviations = []

        for item in response['results']:
            d = Deviation()
            d.from_dict(item)
            deviations.append(d)

        if "name" in response:
            name = response['name']
        else:
            name = None

        return {
            "results" : deviations,
            "name" : name,
            "has_more" : response['has_more'],
            "next_offset" : response['next_offset']
        }