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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 RdatabasesBM(host=rbiomart_host):
 """ Lists BioMart databases through a RPY2 connection. :param host: address of the host server, default='www.ensembl.org' :returns: nothing """

    biomaRt = importr("biomaRt")
    print(biomaRt.listMarts(host=host))