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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 table(schema, name=None):
 """ Create an unbound Ibis table for creating expressions. Cannot be executed without being bound to some physical table. Useful for testing Parameters schema : ibis Schema name : string, default None Name for table Returns ------- table : TableExpr """

    if not isinstance(schema, Schema):
        if isinstance(schema, dict):
            schema = Schema.from_dict(schema)
        else:
            schema = Schema.from_tuples(schema)

    node = ops.UnboundTable(schema, name=name)
    return node.to_expr()