>>> from snowflake.snowpark.types import StructField, VariantType
>>> df = session.create_dataframe([[True, 'X']], schema=["a", "b"])
>>> df.select(is_boolean(to_variant(df["a"])).alias("boolean"), is_boolean(to_variant(df["b"])).alias("varchar")).collect()
[Row(BOOLEAN=True, VARCHAR=False)]