title: How to inherit OAuth2AuthenticationProcessingFilter or add custom filter
body: <p>I am using OAuth2 token in rest based API. I wanted to override OAuth2AuthenticationProcessingFilter so that I can extract token if not provider in header attribute as Authorization(This could be provided as accessToken attribute in header long story don't ask why).
  Or 
  if not then can anyone tell me how to add another filter after the OAuth2AuthenticationProcessingFilter ?</p>