docs: public static String getAutoGenDDLFromJar(InMemoryJarfile jarfile)
              throws IOException
      {
          // Read the raw auto generated ddl bytes.
          byte[] ddlBytes = jarfile.get(VoltCompiler.AUTOGEN_DDL_FILE_NAME);
          if (ddlBytes == null) {
              throw new IOException("Auto generated schema DDL not found - please make sure the database is initialized with valid schema.");
          }
          String ddl = new String(ddlBytes, StandardCharsets.UTF_8);
          return ddl.trim();
      }