docs: public static String print(Doc doc) {
          final StringBuilder builder = new StringBuilder(doc.pkg.name.isEmpty() ? "" : ("package " + doc.pkg.name + "\n\n"));
          if (!doc.imports.isEmpty()) {
              for (Imprt imp : doc.imports) {
                  builder.append("import " + imp.name + "\n");
              }
              builder.append("\n");
          }
          for (DataType dataType : doc.dataTypes) {
              builder.append(print(dataType));
              builder.append("\n");
          }
          return builder.toString();  
          
      }