class GraphQL::Language::Nodes::AbstractNode

def inherited(child_class)

Add a default `#visit_method` and `#children_method_name` using the class name 
def inherited(child_class)
  super
  name_underscored = child_class.name
    .split("::").last
    .gsub(/([a-z])([A-Z])/,'\1_\2') # insert underscores
    .downcase # remove caps
  child_class.module_eval <<-RUBY
    def visit_method
      :on_#{name_underscored}
    end
    class << self
      attr_accessor :children_method_name
    end
    self.children_method_name = :#{name_underscored}s
  RUBY
end