docs: private TransactionException labelTaken(SchemaConcept schemaConcept) {
          if (Schema.MetaSchema.isMetaLabel(schemaConcept.label())) {
              return TransactionException.reservedLabel(schemaConcept.label());
          }
          return PropertyNotUniqueException.cannotCreateProperty(schemaConcept, Schema.VertexProperty.SCHEMA_LABEL, schemaConcept.label());
      }