code: public String generateExistingClassCodeForTable(final TableModel table) {
          final ST template = this.stGroup.getInstanceOf("existingTableClass");
          LOG.debug("Filling template...");
          template.add("table", table);
  
          LOG.debug("Rendering template...");
          return template.render();
      }
docs: Generates the java code for the class representing a entity that is already in the database but needs to be referenced from entities that
  should be created by RedG.
  <p>
  All the data are taken from the {@link TableModel}, which was filled by a {@link com.btc.redg.generator.extractor.TableExtractor} (normally used by the
  {@link com.btc.redg.generator.extractor.MetadataExtractor})
  <p>
  The generated class extends the class generated by {@link #generateCodeForTable(TableModel, boolean)} and overwrites its methods, throwing
  {@link UnsupportedOperationException} for each field access except getting the value of the primary keys.
  
  @param table The extracted table model to generate code for
  @return The generated source code