code: FunctionTypeBuilder inferParameterTypes(JSDocInfo info) {
      // Create a fake args parent.
      Node lp = IR.paramList();
      for (String name : info.getParameterNames()) {
        lp.addChildToBack(IR.name(name));
      }
  
      return inferParameterTypes(lp, info);
    }
docs: Infer the parameter types from the doc info alone.