def METHOD_NAME(self):
    '''
    reads out the file
    '''    
    # these ds_url should always be present in a resonator measurement
    ds_url_amp = "/entry/data0/amplitude"
    ds_url_pha = "/entry/data0/phase"
    ds_url_freq = "/entry/data0/frequency"
    self._ds_amp = self._hf.get_dataset(ds_url_amp)
    self._ds_pha = self._hf.get_dataset(ds_url_pha)
    self._amplitude = np.array(self._hf[ds_url_amp],dtype=np.float64)
    self._phase = np.array(self._hf[ds_url_pha],dtype=np.float64)
    self._frequency = np.array(self._hf[ds_url_freq],dtype=np.float64)
    self._x_co = self._hf.get_dataset(self._ds_amp.x_ds_url)
    self._prepared_datasets = True