':param value: authentication credential object of one of the classes
from  `pika.credentials.VALID_TYPES`'

@credentials.setter
def credentials(self, value):

    if (not isinstance(value, tuple(pika_credentials.VALID_TYPES))):
        raise TypeError(('Credentials    must    be    an    object    of    type:    %r,    but    got    %r' % (pika_credentials.VALID_TYPES, value)))
    self._credentials = copy.deepcopy(value)
