def METHOD_NAME():
    source = [
        ["id", "last_name", "first_name", "language"],
        [1, "Alex", "John", "English"],
        [2, "Peters", "John", "Afrikaans"],
        [3, "Smith", "Paul", None],
    ]
    schema = Schema.from_descriptor(
        {
            "fields": [
                {"name": "id", "type": "number"},
                {"name": "language", "type": "string", "constraints": {"required": True}},
                {"name": "country", "type": "string"},
            ]
        }
    )
    detector = Detector(schema_sync=True)
    resource = TableResource(data=source, schema=schema, detector=detector)
    report = resource.validate()
    assert report.flatten(["rowNumber", "fieldNumber", "type", "cells"]) == [
        [4, 4, "constraint-error", ["3", "Smith", "Paul", ""]],
    ]