code: @Override
      public HttpFilterBuilder containsHeader(final String name) {
  
          return addFilter(new RequestFilter<HttpRequest>() {
  
              @Override
              public boolean matches(HttpRequest request) {
  
                  return request.containsHeader(name);
              }
  
              @Override
              public String toString() {
                  return String.format("containsHeader('%s')", name);
              }
          });
      }
docs: {@inheritDoc}