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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 _indexes_to_secondary_files(gresources, genome_build):
 """Convert a list of genome indexes into a single file plus secondary files. This ensures that all indices are staged together in a single directory. """

    out = {}
    for refname, val in gresources.items():
        if isinstance(val, dict) and "indexes" in val:
            # list of indexes -- aligners
            if len(val.keys()) == 1:
                indexes = sorted(val["indexes"])
                if len(indexes) == 0:
                    if refname not in alignment.allow_noindices():
                        raise ValueError("Did not find indexes for %s: %s" % (refname, val))
                elif len(indexes) == 1:
                    val = {"indexes": indexes[0]}
                else:
                    val = {"indexes": {"base": indexes[0], "indexes": indexes[1:]}}
            # directory plus indexes -- snpEff
            elif "base" in val and os.path.isdir(val["base"]) and len(val["indexes"]) > 0:
                indexes = val["indexes"]
                val = {"base": indexes[0], "indexes": indexes[1:]}
        elif isinstance(val, dict) and genome_build in val:
            val = _indexes_to_secondary_files(val, genome_build)
        out[refname] = val
    return out