def __init__(self, operation,  mimetype):
        self.operation = operation
        self.mimetype = mimetype
:param spec: (optional) token for identifying version. spec can be
dataset/ETHPy150Open zalando/connexion/connexion/decorators/response.py/ResponseValidator.__init__--crossover with--dataset/ETHPy150Open vcstools/vcstools/src/vcstools/hg.py/HgClient.get_version