code: protected Map<ByteBuffer, AbstractType> getValidatorMap(CfDef cfDef) throws IOException
      {
          Map<ByteBuffer, AbstractType> validators = new HashMap<ByteBuffer, AbstractType>();
          for (ColumnDef cd : cfDef.getColumn_metadata())
          {
              if (cd.getValidation_class() != null && !cd.getValidation_class().isEmpty())
              {
                  AbstractType validator = null;
                  try
                  {
                      validator = TypeParser.parse(cd.getValidation_class());
                      if (validator instanceof CounterColumnType)
                          validator = LongType.instance; 
                      validators.put(cd.name, validator);
                  }
                  catch (ConfigurationException e)
                  {
                      throw new IOException(e);
                  }
                  catch (SyntaxException e)
                  {
                      throw new IOException(e);
                  }
              }
          }
          return validators;
      }
docs: get the validators