Lists BioMart filters for a specific dataset.

    :param dataset: dataset to list filters of.
    :param host: address of the host server, default='http://www.ensembl.org/biomart'

    :returns: nothing

def filtersBM(dataset,host=biomart_host):
    """
    Lists BioMart filters for a specific dataset.

    :param dataset: dataset to list filters of.
    :param host: address of the host server, default='http://www.ensembl.org/biomart'

    :returns: nothing

    """
    stdout_ = sys.stdout #Keep track of the previous value.
    stream = StringIO()
    sys.stdout = stream   
    server = BiomartServer(host)
    d=server.datasets[dataset]
    d.show_filters()
    sys.stdout = stdout_ # restore the previous stdout.
    variable = stream.getvalue() 
    v=variable.replace("{"," ") 
    v=v.replace("}"," ") 
    v=v.replace(": ","\t")
    print(v)