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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 connect(self):
 """connect to the various databases, the credientals and settings of which are found in the sherlock settings file **Return:** - ``transientsDbConn`` -- the database hosting the transient source data - ``cataloguesDbConn`` -- connection to the database hosting the contextual catalogues the transients are to be crossmatched against - ``pmDbConn`` -- connection to the PESSTO Marshall database See the class docstring for usage .. todo :: - update key arguments values and definitions with defaults - update return values and definitions - update usage examples and text - update docstring text - check sublime snippet exists - clip any useful text to docs mindmap - regenerate the docs and check redendering of this docstring """

        self.log.debug('starting the ``get`` method')

        transientSettings = self.settings[
            "database settings"]["transients"]
        catalogueSettings = self.settings[
            "database settings"]["static catalogues"]
        if "pessto marshall" in self.settings[
                "database settings"]:
            marshallSettings = self.settings[
                "database settings"]["pessto marshall"]
        else:
            marshallSettings = False

        dbConns = []
        for dbSettings in [transientSettings, catalogueSettings, marshallSettings]:
            port = False
            if dbSettings and dbSettings["tunnel"]:
                port = self._setup_tunnel(
                    tunnelParameters=dbSettings["tunnel"]
                )

            if dbSettings:
                # SETUP A DATABASE CONNECTION FOR THE STATIC CATALOGUES
                host = dbSettings["host"]
                user = dbSettings["user"]
                passwd = dbSettings["password"]
                dbName = dbSettings["db"]
                thisConn = ms.connect(
                    host=host,
                    user=user,
                    passwd=passwd,
                    db=dbName,
                    port=port,
                    use_unicode=True,
                    charset='utf8',
                    client_flag=ms.constants.CLIENT.MULTI_STATEMENTS,
                    connect_timeout=3600
                )
                thisConn.autocommit(True)
                dbConns.append(thisConn)
            else:
                dbConns.append(None)

        # CREATE A DICTIONARY OF DATABASES
        dbConns = {
            "transients": dbConns[0],
            "catalogues": dbConns[1],
            "marshall": dbConns[2]
        }

        dbVersions = {}
        for k, v in dbConns.iteritems():
            if v:
                sqlQuery = u"""
                    SELECT VERSION() as v;
                """ % locals()
                rows = readquery(
                    log=self.log,
                    sqlQuery=sqlQuery,
                    dbConn=v,
                    quiet=False
                )
                version = rows[0]['v']
                dbVersions[k] = version
            else:
                dbVersions[k] = None

        self.log.debug('completed the ``get`` method')
        return dbConns, dbVersions