code: public static CRestBuilder placeholder(String placeholder, String value){
          return new CRestBuilder().placeholder(placeholder, value);
      }
docs: <p>Adds the given placeholder to the string-based annotations placeholders replacement map.</p>
  @param placeholder the placeholder to be replaced
  @param value the value to replace the placeholder with in string-based annotations
  @return a CRestBuilder instance
  @see org.codegist.crest.CRestBuilder#placeholder(String, String)