code: private void addSymbolsFromSettings() {
          if (!Utils.isNullOrEmpty(context.getSettings().getImportsFile())) {
              Symbols imported = new Symbols();
              for (String name : context.getSettings().getImportsFile().split(";")) {
                  try {
                      InputStream is = Utils.getFileOrResource(name);
                      Symbols symbol = JAXB.unmarshal(is, Symbols.class);
                      is.close();
                      imported.getSymbols().addAll(symbol.getSymbols());
                  } catch (IOException e) {
                      throw new RuntimeException("Failed to read imports: " + e.getMessage());
                  }
              }
              if (Utils.isNullOrEmpty(context.getSettings().getImportFilter())) {
                  imports.getSymbols().addAll(imported.getSymbols());
              } else {
                  Pattern regex = Pattern.compile(context.getSettings().getImportFilter());
                  for (String symbol : imported.getSymbols()) {
                      if (regex.matcher(symbol).matches()) {
                          imports.getSymbols().add(symbol);
                      }
                  }
              }
          }
      }
docs: Reads the imports files to construct the list of import symbols to use.