code: private void onSetKeyValidation(CfDef cfDef, Properties cfProperties, StringBuilder builder)
      {
          String keyValidationClass = cfProperties.getProperty(CassandraConstants.KEY_VALIDATION_CLASS);
          if (keyValidationClass != null)
          {
              if (builder != null)
              {
                  // nothing available.
              }
              else
              {
                  cfDef.setKey_validation_class(keyValidationClass);
              }
          }
      }
docs: On set key validation.
  
  @param cfDef
  the cf def
  @param cfProperties
  the cf properties
  @param builder
  the builder