code: @Override
      public boolean isValid(Object input) {
          int value;
          try {
              value = Integer.parseInt(input.toString());
          } catch (NumberFormatException e) {
              return false;
          }
  
          if (minAllowedValue != null && value < minAllowedValue)
              return false;
          if (maxAllowedValue != null && value > maxAllowedValue)
              return false;
          return true;
      }
docs: Is the given object valid for this column,
  given the column type and any
  restrictions given by the
  ColumnMetaData object?
  
  @param input object to check
  @return true if value, false if invalid