code: private void onDiscriminatorColumn(StringBuilder builder, StringBuilder columnBuilder, EntityType entityType)
      {
          String discrColumn = ((AbstractManagedType) entityType).getDiscriminatorColumn();
          String discrValue = ((AbstractManagedType) entityType).getDiscriminatorValue();
  
          // No need to check for empty or blank, as considering it as valid name
          // for nosql!
          if (discrColumn != null && discrValue != null)
          {
              appendValue(builder, String.class, discrValue, false);
              builder.append(Constants.COMMA);
              appendColumnName(columnBuilder, discrColumn);
              columnBuilder.append(Constants.COMMA); // because only key columns
  
          }
      }
docs: On discriminator column.
  
  @param builder
  the builder
  @param columnBuilder
  the column builder
  @param entityType
  the entity type