title: How can i get the `signature` field of java reflection Method object
body: <p>i'm using ASM to build class file base on another <code>Interface</code> , i could use java reflection to get methods of the <code>Interface</code> , but i need to get the signature of it . 
  <a href="https://i.stack.imgur.com/MoGP1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/MoGP1.png" alt="enter image description here"></a></p>
  
  <p>i found it's a private field , and there's no direct method to get it . is there any way out ? i use jdk7 . 
  tks advance .</p>