docs: public boolean supportsConvert(int fromType,
                                     int toType) throws SQLException {
  
  //#ifdef JAVA6
          switch (fromType) {
  
              case java.sql.Types.NCHAR : {
                  fromType = java.sql.Types.CHAR;
  
                  break;
              }
              case java.sql.Types.NCLOB : {
                  fromType = java.sql.Types.CLOB;
  
                  break;
              }
              case java.sql.Types.NVARCHAR : {
                  fromType = java.sql.Types.VARCHAR;
  
                  break;
              }
          }
  
          switch (toType) {
  
              case java.sql.Types.NCHAR : {
                  toType = java.sql.Types.CHAR;
  
                  break;
              }
              case java.sql.Types.NCLOB : {
                  toType = java.sql.Types.CLOB;
  
                  break;
              }
              case java.sql.Types.NVARCHAR : {
                  toType = java.sql.Types.VARCHAR;
  
                  break;
              }
          }
  
  //#endif JAVA6
          Type from = Type.getDefaultType(Type.getHSQLDBTypeCode(fromType));
          Type to   = Type.getDefaultType(Type.getHSQLDBTypeCode(toType));
  
          if (from == null || to == null) {
              return false;
          }
  
          return to.canConvertFrom(from);
      }