docs: public String getUsername() {
          final String username = basicJdbcConfiguration.getConfiguredUsername();
          if (calculatedUsername == null || StringUtils.hasText(username)) {
              calculatedUsername = username;
              if (!StringUtils.hasText(calculatedUsername) && JdbcDatabaseManager.isEmbedded(basicJdbcConfiguration.getDriverClassName())) {
                  calculatedUsername = "sa";
              }
          }
  
          return calculatedUsername;
      }