code: public String getFunctionName(ExecutableElement method) {
      String name = ElementUtil.getSelector(method);
      if (name == null) {
        name = getRenamedMethodName(method);
      }
      if (name != null) {
        return name.replaceAll(":", "_");
      } else {
        return addParamNames(method, getMethodName(method), '_');
      }
    }
docs: Returns an appropriate name to use for this method as a function. This name
  is guaranteed to be unique within the declaring class, if no methods in the
  class have a renaming. The returned name should be given an appropriate
  prefix to avoid collisions with methods from other classes.