code: @Override
  	public LexemeDocument withStatement(Statement statement) {
  		Map<String, List<Statement>> newGroups = addStatementToGroups(statement, claims);
  		return new LexemeDocumentImpl(getEntityId(), lexicalCategory,
  				language, lemmas, newGroups, forms, revisionId);
  	}
docs: /*
  LexemeIdValue id,
  ItemIdValue lexicalCategory,
  ItemIdValue language,
  Map<String, MonolingualTextValue> lemmas,
  Map<String, List<Statement>> statements,
  List<FormDocument> forms,
  long revisionId
  (non-Javadoc)
  @see org.wikidata.wdtk.datamodel.interfaces.StatementDocument#withStatement(org.wikidata.wdtk.datamodel.interfaces.Statement)