docs: protected void countStatements(UsageStatistics usageStatistics,
  			StatementDocument statementDocument) {
  		// Count Statement data:
  		for (StatementGroup sg : statementDocument.getStatementGroups()) {
  			// Count Statements:
  			usageStatistics.countStatements += sg.size();
  
  			// Count uses of properties in Statements:
  			countPropertyMain(usageStatistics, sg.getProperty(), sg.size());
  			for (Statement s : sg) {
  				for (SnakGroup q : s.getQualifiers()) {
  					countPropertyQualifier(usageStatistics, q.getProperty(), q.size());
  				}
  				for (Reference r : s.getReferences()) {
  					usageStatistics.countReferencedStatements++;
  					for (SnakGroup snakGroup : r.getSnakGroups()) {
  						countPropertyReference(usageStatistics,
  								snakGroup.getProperty(), snakGroup.size());
  					}
  				}
  			}
  		}
  	}