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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 MRA(biomf, sampleIDs=None, transform=None):
 """ Calculate the mean relative abundance percentage. :type biomf: A BIOM file. :param biomf: OTU table format. :type sampleIDs: list :param sampleIDs: A list of sample id's from BIOM format OTU table. :param transform: Mathematical function which is used to transform smax to another format. By default, the function has been set to None. :rtype: dict :return: A dictionary keyed on OTUID's and their mean relative abundance for a given number of sampleIDs. """

    ra = relative_abundance(biomf, sampleIDs)
    if transform is not None:
        ra = {sample: {otuID: transform(abd) for otuID, abd in ra[sample].items()}
              for sample in ra.keys()}
    otuIDs = biomf.ids(axis="observation")
    return mean_otu_pct_abundance(ra, otuIDs)