@staticmethod
def reads(err_log):
    """
        Parse the outputs from bbmerge to extract the total number of reads, as well as the number of reads that
        could be paired
        :param err_log: bbmerge outputs the stats in the error file
        :return: num_reads, the total number of reads, paired_reads, number of paired readds
        """
    num_reads = 0
    paired_reads = 0
    with open(err_log, 'r') as error_log:
        for line in error_log:
            if 'Pairs:' in line:
                num_reads = line.split('\t')[-1].rstrip()
            elif 'Joined:' in line:
                paired_reads = line.split('\t')[-2].rstrip()
    return num_reads, paired_reads
