code: private void writePrefixDeclaration(BufferedWriter writer) throws IOException {
          final ImmutableMap<String, String> prefixMap = ppMapping.getMetadata().getPrefixManager().getPrefixMap();
  
          if (prefixMap.size() == 0) {
              return; // do nothing if there is no prefixes to write
          }
  
          writer.write(OntopNativeMappingParser.PREFIX_DECLARATION_TAG);
          writer.write("\n");
          for (String prefix : prefixMap.keySet()) {
              String uri = prefixMap.get(prefix);
              writer.write(prefix + (prefix.length() >= 9 ? "\t" : "\t\t") + uri + "\n");
          }
          writer.write("\n");
      }
docs: /*
  Helper methods related to save file.