<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def set_used_labels(self, labels):
 """ Specify which trials to use in subsequent analysis steps. This function masks trials based on their class labels. Parameters labels : list of class labels Marks all trials that have a label that is in the `labels` list for further processing. Returns ------- self : Workspace The Workspace object. """

        mask = np.zeros(self.cl_.size, dtype=bool)
        for l in labels:
            mask = np.logical_or(mask, self.cl_ == l)
        self.trial_mask_ = mask
        return self