code: public HttpRequest withHeader(String name, String... values) {
          this.headers.withEntry(header(name, values));
          return this;
      }
docs: Adds one header to match which can specified using plain strings or regular expressions
  (for more details of the supported regex syntax see http://docs.oracle.com/javase/6/docs/api/java/util/regex/Pattern.html)
  
  @param name   the header name
  @param values the header values which can be a varags of strings or regular expressions