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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 giant_text_sqltype(dialect: Dialect) -> str: """ Returns the SQL column type used to make very large text columns for a given dialect. Args: dialect: a SQLAlchemy :class:`Dialect` Returns: the SQL data type of "giant text", typically 'LONGTEXT' for MySQL and 'NVARCHAR(MAX)' for SQL Server. """

    if dialect.name == SqlaDialectName.SQLSERVER:
        return 'NVARCHAR(MAX)'
    elif dialect.name == SqlaDialectName.MYSQL:
        return 'LONGTEXT'
    else:
        raise ValueError("Unknown dialect: {}".format(dialect.name))