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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 check_attribute_mapping_exists(resource_attr_id_source, resource_attr_id_target, **kwargs):
 """ Check whether an attribute mapping exists between a source and target resource attribute. returns 'Y' if a mapping exists. Returns 'N' in all other cases. """

    qry = db.DBSession.query(ResourceAttrMap).filter(
                ResourceAttrMap.resource_attr_id_a == resource_attr_id_source,
                ResourceAttrMap.resource_attr_id_b == resource_attr_id_target).all()

    if len(qry) > 0:
        return 'Y'
    else:
        return 'N'