code: public void setHeaders(final Set<String> names) {
          // transform to lower-case because header names should be case-insensitive
          Set<String> lowerCaseNames = new HashSet<>();
          for (String name: names) {
              lowerCaseNames.add(name.toLowerCase());
          }
          this.headerNames = lowerCaseNames;
      }
docs: Set the header names to forward from the request.  Should not be defined if all is set to true
  
  @param names the header names.