code: function ancestor(predicate, node) {
      while ((node = node.parent)) {
          if (predicate(node)) return true;
      }
  
      return false;
  }
docs: Determine if `node` has an ancestor satisfying `predicate`.
  @param   {Function} predicate - predicate to test each ancestor against
  @param   {ASTNode} node - child node to begin search at
  @returns {Boolean} true if an ancestor satisfies `predicate`