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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 _is_finished_dumping(directory):
 """Determine if the sequencing directory has all files. The final checkpoint file will differ depending if we are a single or paired end run. """

    #if _is_finished_dumping_checkpoint(directory):
    #    return True
    # Check final output files; handles both HiSeq and GAII
    run_info = os.path.join(directory, "RunInfo.xml")
    hi_seq_checkpoint = "Basecalling_Netcopy_complete_Read%s.txt" % \
                        _expected_reads(run_info)
    to_check = ["Basecalling_Netcopy_complete_SINGLEREAD.txt",
                "Basecalling_Netcopy_complete_READ2.txt",
                hi_seq_checkpoint]
    return reduce(operator.or_,
                  [os.path.exists(os.path.join(directory, f)) for f in to_check])