docs: private int getIsoLevel(String isoLevel)
      {
          if (isoLevel.equalsIgnoreCase(LITERAL_IL_READ_UNCOMMITTED))
          {
              return IL_READ_UNCOMMITTED;
          }
          else if (isoLevel.equalsIgnoreCase(LITERAL_IL_READ_COMMITTED))
          {
              return IL_READ_COMMITTED;
          }
          else if (isoLevel.equalsIgnoreCase(LITERAL_IL_REPEATABLE_READ))
          {
              return IL_REPEATABLE_READ;
          }
          else if (isoLevel.equalsIgnoreCase(LITERAL_IL_SERIALIZABLE))
          {
              return IL_SERIALIZABLE;
          }
          else if (isoLevel.equalsIgnoreCase(LITERAL_IL_OPTIMISTIC))
          {
              return IL_OPTIMISTIC;
          }
          //logger.warn("unknown isolation-level: " + isoLevel + " using RW_UNCOMMITTED as default");
          return defIsoLevel;
      }