### Question:
LuceneDocumentStructure { public static boolean useFieldForUniquenessVerification( String fieldName ) { return !LuceneDocumentStructure.NODE_ID_KEY.equals( fieldName ) && ValueEncoding.fieldPropertyNumber( fieldName ) == 0; } private  LuceneDocumentStructure(); static Document documentRepresentingProperties( long nodeId, Value... values ); static String encodedStringValuesForSampling( Value... values ); static MatchAllDocsQuery newScanQuery(); static Query newSeekQuery( Value... values ); static NumericRangeQuery<Double> newInclusiveNumericRangeSeekQuery( Number lower, Number upper ); static Query newRangeSeekByStringQuery( String lower, boolean includeLower,
            String upper, boolean includeUpper ); static Query newWildCardStringQuery( String searchFor ); static Query newRangeSeekByPrefixQuery( String prefix ); static Query newSuffixStringQuery( String suffix ); static Term newTermForChangeOrRemove( long nodeId ); static long getNodeId( Document from ); static TermsEnum originalTerms( Terms terms, String fieldKey ); static Field encodeValueField( Value value ); static boolean useFieldForUniquenessVerification( String fieldName ); static final String NODE_ID_KEY; static final String DELIMITER; }### Answer:
@Test void checkFieldUsageForUniquenessVerification() { assertFalse( useFieldForUniquenessVerification( "id" ) ); assertFalse( useFieldForUniquenessVerification( "1number" ) ); assertTrue( useFieldForUniquenessVerification( "number" ) ); assertFalse( useFieldForUniquenessVerification( "1string" ) ); assertFalse( useFieldForUniquenessVerification( "10string" ) ); assertTrue( useFieldForUniquenessVerification( "string" ) ); }