ConceptRelationFilter
final case class ConceptRelationFilter(idOption: Option[String], sourceNameOrExpr: ENameValueOrExpr, linkroleOrExpr: StringValueOrExpr, linknameOrExprOption: Option[ENameValueOrExpr], arcroleOrExpr: StringValueOrExpr, arcnameOrExprOption: Option[ENameValueOrExpr], axis: Axis, generationsOption: Option[Int], exprOption: Option[ScopedXPathString]) extends Filter