Check the signal type of the experiment

        Returns
        -------
        True, if the signal type is supported, False otherwise

        Raises
        ------
        Warning if the signal type is not supported

def _check_experiment(self, name):
        """Check the signal type of the experiment

        Returns
        -------
        True, if the signal type is supported, False otherwise

        Raises
        ------
        Warning if the signal type is not supported
        """
        with h5py.File(name=self.path, mode="r") as h5:
            sigpath = "/Experiments/{}/metadata/Signal".format(name)
            signal_type = h5[sigpath].attrs["signal_type"]
        if signal_type != "hologram":
            msg = "Signal type '{}' not supported: {}[{}]".format(signal_type,
                                                                  self.path,
                                                                  name)
            warnings.warn(msg, WrongSignalTypeWarnging)
        return signal_type == "hologram"