code: public void parse(SourceMapObject sourceMapObject, SourceMapSupplier sectionSupplier)
        throws SourceMapParseException {
      if (sourceMapObject.getVersion() != 3) {
        throw new SourceMapParseException("Unknown version: " + sourceMapObject.getVersion());
      }
  
      String file = sourceMapObject.getFile();
      if (file != null && file.isEmpty()) {
        throw new SourceMapParseException("File entry is empty");
      }
  
      if (sourceMapObject.getSections() != null) {
        // Looks like a index map, try to parse it that way.
        parseMetaMap(sourceMapObject, sectionSupplier);
        return;
      }
  
      lineCount = sourceMapObject.getLineCount();
      sourceRoot = sourceMapObject.getSourceRoot();
      sources = sourceMapObject.getSources();
      sourcesContent = sourceMapObject.getSourcesContent();
      names = sourceMapObject.getNames();
  
      if (lineCount >= 0) {
        lines = new ArrayList<>(lineCount);
      } else {
        lines = new ArrayList<>();
      }
  
      // The value type of each extension is the native JSON type (e.g. JsonObject, or JSONObject
      // when compiled with GWT).
      extensions.putAll(sourceMapObject.getExtensions());
      new MappingBuilder(sourceMapObject.getMappings()).build();
    }
docs: Parses the given contents containing a source map.