code: @Override
      public Method resolveFunction(String prefix, String localName) {
          return (Method) this.fnmap.get(prefix + ":" + localName);
      }
docs: Resolves the specified local name and prefix into a Java.lang.Method.
  Returns null if the prefix and local name are not found.
  
  @param prefix the prefix of the function
  @param localName the short name of the function
  @return the result of the method mapping. Null means no entry found.