code: public void resolveExpressions(final WordprocessingMLPackage document, ProxyBuilder<T> proxyBuilder) {
      try {
        final T expressionContext = proxyBuilder.build();
        CoordinatesWalker walker = new BaseCoordinatesWalker(document) {
          @Override
          protected void onParagraph(ParagraphCoordinates paragraphCoordinates) {
            resolveExpressionsForParagraph(paragraphCoordinates.getParagraph(), expressionContext, document);
          }
        };
        walker.walk();
      } catch (ProxyException e) {
        throw new DocxStamperException("could not create proxy around context root!", e);
      }
    }
docs: Finds expressions in a document and resolves them against the specified context object. The expressions in the
  document are then replaced by the resolved values.
  
  @param document          the document in which to replace all expressions.
  @param proxyBuilder      builder for a proxy around the context root to customize its interface