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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 drop_keyspace(name, connections=None):
 """ Drops a keyspace, if it exists. *There are plans to guard schema-modifying functions with an environment-driven conditional.* **This function should be used with caution, especially in production environments. Take care to execute schema modifications in a single context (i.e. not concurrently with other clients).** :param str name: name of keyspace to drop :param list connections: List of connection names """

    if not _allow_schema_modification():
        return

    if connections:
        if not isinstance(connections, (list, tuple)):
            raise ValueError('Connections must be a list or a tuple.')

    def _drop_keyspace(name, connection=None):
        cluster = get_cluster(connection)
        if name in cluster.metadata.keyspaces:
            execute("DROP KEYSPACE {0}".format(metadata.protect_name(name)), connection=connection)

    if connections:
        for connection in connections:
            _drop_keyspace(name, connection)
    else:
        _drop_keyspace(name)