code: private AbstractType<?> getValidatorForValue(CfDef cfDef, byte[] columnNameInBytes)
      {
          String defaultValidator = cfDef.default_validation_class;
  
          for (ColumnDef columnDefinition : cfDef.getColumn_metadata())
          {
              byte[] nameInBytes = columnDefinition.getName();
  
              if (Arrays.equals(nameInBytes, columnNameInBytes))
              {
                  return getFormatType(columnDefinition.getValidation_class());
              }
          }
  
          if (defaultValidator != null && !defaultValidator.isEmpty())
          {
              return getFormatType(defaultValidator);
          }
  
          return null;
      }
docs: Get validator for specific column value
  @param cfDef - CfDef object representing column family with metadata
  @param columnNameInBytes - column name as byte array
  @return AbstractType - validator for column value