def METHOD_NAME(
    self, loader: Loader, target_class: Optional[str] = None
) -> ValidationReport:
    """Validate instances from a data source
    :param loader: An instance of a subclass of `linkml.validator.loaders.Loader`
        which provides the instances to validate
    :param target_class: Name of the class within the schema to validate
        against. If None, the class will be inferred from the schema by
        looked for a class with `tree_root: true`. Defaults to None.
    :return: A validation report
    :rtype: ValidationReport
    """
    return ValidationReport(results=list(self.iter_results_from_source(loader, target_class)))