title: R, R6, Get Full Class Name from R6Generator Object
body: <p>In R6, How can I get the full list of class inheritances, without creating instances of the generator objects?</p>
  
  <p>Consider the following:</p>
  
  <pre><code>A = R6::R6Class("Base",NULL)
  B = R6::R6Class("Top",inherit = A)
  class(B)     #Returns 'R6ClassGenerator'
  B$classname  #Returns 'Top' 
  </code></pre>
  
  <p>What I want is <code>c('Top','Base','R6')</code></p>
  
  <p>In other words, what would otherwise be returned by <code>class(B$new())</code></p>
  
  <p>In the real world, I have a complex set of inheritances, and, initializers with many arguments, some without default values, so I am trying to avoid instantiating a new object in order to obtain this information.</p>