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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def load_cufflinks(self, filter_ok=True):
 """ Load a Cufflinks gene expression data for a cohort Parameters filter_ok : bool, optional If true, filter Cufflinks data to row with FPKM_status == "OK" Returns ------- cufflinks_data : Pandas dataframe Pandas dataframe with Cufflinks data for all patients columns include patient_id, gene_id, gene_short_name, FPKM, FPKM_conf_lo, FPKM_conf_hi """

        return \
            pd.concat(
                [self._load_single_patient_cufflinks(patient, filter_ok) for patient in self],
                copy=False
        )