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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_gvcf_file(in_file):
 """Check if an input file is raw gVCF """

    to_check = 100
    n = 0
    with utils.open_gzipsafe(in_file) as in_handle:
        for line in in_handle:
            if not line.startswith("##"):
                if n > to_check:
                    break
                n += 1
                parts = line.split("\t")
                # GATK
                if parts[4] == "<NON_REF>":
                    return True
                # strelka2
                if parts[4] == "." and parts[7].startswith("BLOCKAVG"):
                    return True
                # freebayes
                if parts[4] == "<*>":
                    return True
                # platypue
                if parts[4] == "N" and parts[6] == "REFCALL":
                    return True